Janna is very strong in poke comps though, because she peels. <
I am sure Janna is very strong in a poke comp. What I said though was that Janna was weak to poke style comps. As in, if you want to counter Janna, play a poke-style support. Although, as I've mentioned, poke-style supporting is under-represented right now, under tuned, so the champions that naturally "Should" counter Janna don't have the presence they need.
If the issue was simply the meta favoring that champion, you'd see a large discrepancy in win rates vs various champions. Look at Vayne for instance - Even though her play rate is #1 and her win rate is currently quite good, she still has many bad matchups for her that drop her win rate to less than 46%. <
This is indeed true, but take a closer look at some of the other champions that "counter" Janna the hardest. Do you notice a common theme?
50.63 %
52.21 %
52.4 %
52.31 %
52.35 % etc etc...
Its only by a few percentage, but enough to take notice. All these supports that show a noticeable decrease are poke champs, which, as I've said before, is a play-style that is a bit under tuned at the moment.
Also, with Vayne, the reason why she's so prominent right now is because :
A) A lot of the top jungles right now are devourer, on-hit type champions that synergies extremely well with Vayne (TLDR: Teamwork is OP) pair her with a Shyvana and shred through tanks like paper.
B) The traditional lane bullies like Lucian have been nerfed and under tuned allowing Vayne's greatest weakness: her early game, to go fairly neutral.
Thinking about this in terms of Janna you see very similar things:
A) A lot of the top supports are tanky-engage supports which Janna Excels at fighting against (Teamwork OP)
B) Janna's greatest weakness: Poke-style supporting is underperforming and don't see a whole lot of play allowing Janna to flourish. (People don't even like upgrading their frost-queen's claim, the poke-support item, They only get the first upgrade and sell it off later for a Nomads or face of the Mountain).
Also, on a side note, why does this web site Cite multiple champions as champions that "counter" Janna, but then show these same champions on the list that Janna counters? trippy.