How can something this slow and this frail with such a terrible typing be considered anything more than a nuisance to all non-stall teams? Stall is literally the only argument Hoopa-U has against it now, because it has been established that having zero counters does not necessarily make a pokemon broken. 9/10 times it's going to be choice-locked & spamming STABs Psyshock & Dark Pulse, and only occasionally using its coverage moves (Focus Miss & Thunderbolt) on what would be super-effective hits (or an obvious switch into one). In that sense, Hoopa is very predictable. Theoretically, it can use [insert moves] instead of what I have mentioned, but the most common set is what we should be discussing. Of course, you usually have to sack a pokemon if Hoopa outspeeds it, but that just means something faster than base 80 speed can come in and threaten it. Hoopa 2HKOs almost everything slower than it, but gets OHKOd by almost anything faster than it & physical. At only base 80 speed, that's incredibly balanced in the non-Hoopa-U's favor. Besides Pursuit & Sucker Punch decimating Hoopa-U's HP, it needs teammates that can tank a U-Turn, tank Gale Wings, reflect Thunderwave, tank/reflect Prankster, tank any physical attack, since its most powerful stab (Hyperspace Fury) lowers its defense. People act like this is the first time a non-Uber pokemon actually needs its opponent to be faster to be defeated. Scary on paper, but surprisingly common. I already listed a number of examples in my previous post, and anymore would be overkill.
If something can be revenged so incredibly easy, by such a wide variety of options, what's really the reason Hoopa-U is so OP other than "Hurr durr, no switch-ins"? The extinction of stall is understandable, but some have mentioned its ability to use both physical and special moves. The fact is, the physical Choice Band set actually has a few counters, which is why it's not worth mentioning. It sucks compared to the special set, since Hoopa-U was still tolerable until you could no longer just stick a Mega Aggron or Dragonite in, forcing you to revenge kill.
All that aside, Hoopa-U isn't overcentralized. I didn't see any increase of obscure Pokemon being used for the sole purpose of killing Hoopa, nor did I see many teams that consists mostly of specific Pokemon and moves centered around its ability to defeat Hoopa. I actually found relatively unchanged teams. Stall has decreased, but all other playstyles have increased. We still got all the typical OU Pokemon we see all the time (Talonflame, Conkeldurr, Lando-T, ect). I don't think that is a bad thing. I never felt the need to really fear for Hoopa-U when teambuilding, since again I just throw out something faster and Hoopa either switches out, dies, or get paralyzed. What more needs to be said?