Oh boy, this has been quite the thread. I will bite a bit tho cause I feel it is important to point out some importants things without using insults or derogatory terms for the sake of feeling superior.
People using their favorite Pokemon regardless of their viability in whatever metagame they want to has been a thing since forever. I have always been respectful of their decisions cause while isnt the correct decision in terms of the competitive aspect of the game, some people just want to fun. The true problem is when the usage statistics are exploited to make a Pokemon that doesnt deserve to be in an upper tier and makes the term usage more of a joke to determine is something is good or not (It has been the case for quite some time now, this just buries the hole even deeper).
What I mean by not deserving it? Simple, Ambipom serves no niche than any other fast attacker cant do better than it. I will now list a couple of mons that do the "Fast Physical Attacker" thing people love about ambipom better than it: Crobat, Zygarde-10% (Thousand Arrows being incredibly spammable in UU and RU as well), Mega Absol, Talonflame, Infernape, Mega Sceptile, Terrakion, even Sneasel and Aerodactyl. And thats not even mentioning the Special attackers. Thats the whole purpose on why there are so many lower tiers in the first place. To allow less viable Pokemon to shine on a metagame where they can stand out for their merits. Ambipom rising to UU for fun makes all this situation a joke of really bad taste cause then you just need to be a celebrity with enough followers to make certain mon rise to a tier that doesnt deserve it and... have to use a derogatory term here sorry... SHIT on the whole system Smogon has worked so hard to stabilize. (It was way worse before, we remember deep sea tooth amoonguss and RU Metang on BW with love).
Cant really hate aim for this since he probably just did it more fun, like Im sure there was no ill intention at all, and he can do whatever he wants anyways, is his content. But this backfired spectacularly. Not much else to do besides dealing with the "burden" I guess. It isnt a problem if a select few uses their favorite Pokemon that are unviable by common consensus since those few dont have an influence like in the past but this... Oh well.