Nice post btw, although I presume it was intended to have a reply so here this is better late than never.
Yes I understand that on the whole you mentioned that the point you were addressing was centered around the "Defog" argument. I think you're seeing it as overstated, simply because that is far from the only reason, but it's the one that tends to crop up the most.
This is because Zapdos is far more than just a Defogger. Zapdos is the only viable option for reliable recovery on Electric, having access to Roost where as barring the, at some times sketchy option of Pain Split on Rotom, every other mon is confined to Rest. This makes Zapdos almost the type's only defensive wall that can consistently last throughout a game. Effectively what I'm saying there, is that without Zapdos, Electric is forced into a team based around Sticky Webs and Hyper Offence, something
Chleg has already raised, but the important point being that Electric doesn't have the offensive and sweeping potential other types such as Rock and Fire have in order to be able to effectively pull off Hyper Offence.
Looking over your post, there were alot of references to the standard OU Monotype tier, but considering this is about UU Monotype, I'll try to bear both in mind to address all the points.
"1. Steel needs Heatran more than electric needs defog."
Here the original point I'd actually like to somewhat agree with considering its specifics. Like you said I can indeed mention the usage stats, being that in the UU Metagame, Heatran is unsurprisingly banned due to usage, something that could potentially happen to Zapdos too. The point here again is that Zapdos is far more than Defog. Yes your post is centralized around that key point, but I would strongly argue that in UU Monotype tier, Electric needs Zapdos just as much as, if not more than Steel would appreciate Heatran.
The replacements for Zapdos on Electric are effectively non-existent. Assuming Rotom sticks around, the only mon that would provide similar amounts of bulk in terms of a wall, would be Stunfisk, a mon without the Ground immunity and using Rest as a form of recovery (Pain Split isn't great with its high HP)... Something hardly ideal, and also unsuitable considering the Hyper Offence build that would be forced.
Now replacements for Heatran. Obviously no direct Fire immunities are supplied, but there are numerous mons that can be extremely effective in sponging up Fire type attacks. S Rank on Steel for a reason, Empoleon is the obvious option, having fantastic Special bulk and also supplying Hazard control. On the Physical side there is also normal Aggron, which whilst having two 4x Weaknesses, does a great job of sponging Physical Fire type attacks. There's also Mega Aggron which takes even super effective hits well thanks to Filter, and can cripple in return with Thunder Wave. Whilst you could argue this is hardly the same as Heatran, not being immune to the attacks, they are similar in that they're both still weak to Ground, and aren't beaten by Heatran in terms of recovery either. And in terms of Fire coverage too, whilst no mons offer the same STAB, mons that perform greatly in the UU Mono Metagame being Durant and Lucario, hit the same types as Fire in Ice, Grass and Steel.
I understand you raised later in the post you mentioned about saying "X Type has Y Mon" and viability, but these are perfectly viable options. I don't like to Theory Mon as I understand Replays are better, but I didn't see much of an option towards the end there. More to the point, also considering the viable screens support and strong offensive options the type still has, to directly use your words, in the UU Monotype Metagame, Steel is indeed "fine and dandy", and I'd strongly advise other people give it a try to prove that.
"2. Ghost literally only has Drifblim for hazard control, because Mega Sableye is banned. But no, electric needs to have defog."
I'm not going to argue that Ghost is a great type in the UU Mono Metagame because it isn't, LTLC and usage stats really didn't do it a favor. It's key offensive options have vanished, but that isn't an aspect that applies to Zapdos, as this is about the Defensive part of the two types. (Again this is about how Zapdos is far more than just Defog, simply being the only form of it for the type) Ignoring the passively aggressive way in which you figured someone (presumably me) would tell you to use Driftblim, I'd just like to point out that no, that's not what I'm telling anyone using Ghost to do.
This isn't as related to your post because I understand you only questioned if Zapdos should be banned towards the end, but here I'm mentioning how Ghost still has it's defensive core of Sableye and Jellicent. Yes it's offense won't be giving them any breaks, but both mons have access to Recover, something I've already mentioned that Electric has almost none of. Jellicent is an extremely viable special wall, and whilst Sableye doesn't possess the same bulk as it's Mega form, it can still viably hold the Mega Stone in order to do a better job at absorbing Knock Offs. For now, the usage system means that the viability of Ghost cannot be helped, but in relation to this post its defensive core still remains relatively in shape, far from what Electric's would be without Zapdos.
"3. Fairy has access to Togekiss in OU, but doesn't use it because they just don't need it. As it turns out, sometimes you don't need hazard control."
This one's relatively simple for whatever context it applies to. I see you've referenced OU Monotype but I understand this should be about the UU Mono tier. I'd just like to bring up a comment I see in "Fairy seems to be doing fine without defog". You may have tried the type in UU and that's fair enough, but I think it's fair to say, and a lot of people would agree with, is that Fairy is hardly a prominent type in UU Mono, not having the same offensive and setup options. Something to note there is that no, I don't think loss of Defog Togekiss, or Magic Bounce in particular is the cause of this.
Sidenote Togetic is actually perfectly viable in UU Mono, but no I'm not trying to force people to use it. Fairy's form of hazard removal/prevention was banned due to usage, and nothing can be done about that. Electric's form of this, assuming usage stats below threshold, will only be banned if it is deemed broken for the tier.
4. Electric doesn't need defog as badly as fire needs hazard control. Seriously man?
Yay a mention, and sorry for the incredulity but even after going back and re-reading it myself, I can assure you the post is about Electric's reliance on Zapdos, far from just Defog itself. (although again I understand that's what your post is centered around)
The comparison to fire was made not off the form of weakness to hazards. However you've already mentioned what Stealth Rocks can do to the type, and not to oblige to your "X type has Y mon" point, but Moltres is actually reasonably reliable in UU Mono despite its rocks weakness, and I could mention Taunt lead Infernape but I understand at this moment in time Electric also has Prankster Taunt Thundurus although that mon in itself is a different discussion.
What I'd like to address here, is that despite losing it's best forms of Hazard removal, Fire is still extremely viable in UU Mono as a form of Hyper Offence. Without Zapdos, this is what Electric would also be forced to try and attempt, however this is where the differences appear. Fire's forms of offence simply blow Electric's away. I'd already mentioned how Electric lacks many powerful attackers who also possess the speed without having to be choiced in some way, where as Fire has the options of Darmanitan, Entei, and Volcarona, the latter being something completely unmatched on Electric in terms of dangerous setup. (No CM Raikou and NP Thundurus do not compare), and almost all types have difficulty switching in to the first two.
(Your fifth point was addressed numerous times throughout the others.)