well just from gen v.
not counting pokemon from gen vi. And lets make it even harder. lets give gliscor poison heal so he cant be poisoned. and I can only use OU pokemon
because roar, and whirlwind are now 100% accurate, and defog has been buffed. using just gen v pokemon, in gen vi, this would be countered by:
via Whirlwind:
Starraptor
hippowdon
skarmory
volcarona
via Roar:
Donphan
Dragonite
Garchomp
Gyrados
Haxorus
Heatran
Hippowdon
Hydreigon
Infernape
Jolteon
Keldeo
Latias
Latios
Lucario
Mamoswine
Ninetales
Salamence
Skarmory
Terrakion
Tyranitar
Vaporeon
Venusaur.
via Defog:
scizor
latias
skarmory
gliscor
flygon
and just for fun death by struggle:
Crobat.
And if you're nitpicky remove everyone of those pokemon that weak to earthquake, and you still have a pretty big list.
I said hard counter, first of all, meaning that a chunk of those Pokemon are still stopped dead in their tracks with the right variant of the moveset. Second of all, note how a majority of the Pokemon you listed do not use Whirlwind or Roar in any of their commonly listed sets. So here is the actual list:
Gyarados
Heatran
Hippowdon
Skarmory
Tyranitar
Vaporeon
Crobat
Flygon
Gliscor
Latias
Scizor
Then we factor in the Pokemon that are shut down by Taunt... Which is anyone using Roar or Whirlwind. So that leaves the Defog users.
Crobat
Flygon
Gliscor
Latias
Scizor
Skarmory
Anyone slower than Gliscor is still shut down by Taunt, so...
Crobat
Flygon
Gliscor
Latias
That finally leaves the fact that Gliscor may have the set of Double Team/Substitute/Ice Fang/Taunt, meaning they're all hit for decent damage from Ice Fang. Meaning this set has no real hard counters, only soft counters. You hear that?
There's no definite way to counter Double Team Gliscor outside of maybe a faster Gliscor or Crobat's Taunt. If the
entire metagame comes down to needing to prepare for one set on one Pokemon, there's clearly something broken and very wrong about using an evasion move on Gliscor.
My point stands. Evasion is broken and purely luck-based.
So? You literally one 19 Battles beforehand. Luck made you lose 1 out of 20 battles. That's why evasion isn't a big deal, because it's never going to do anything more then change the results of one or two fights.
None of the 19 battles beforehand used Double Team. The battle involving Double Team made me lose. That is why it's completely a big deal.