Not at all. That is 100% not my point, and I don't quite understand where you got that from. My point is that "this otherwise completely unviable Pokemon counters the strategy/Poke in question, therefore the strategy/Poke in question is not overpowered" has never been considered a strong argument. There is literally not a single Poke or strategy in the game that can't be checked or countered in some way, but the existence of a counter has never prevented bans from happening. Running a whole team of Insomnia Pokes is a counter to Spore spamming, but it's not healthy for the metagame to have to do that, so we have the Sleep Clause.
It is a particularly weak argument when something like Numel is completely useless in OU outside of countering this strategy. I do not believe for a second that you carry a Numel on your team and have no problem doing it because it allows you to counter SwagPlay.