Well if anything, the tuning should probably be on Unstoppable Force rather than Thunder Clap itself.
But more importantly, it's questionable if a nerf is needed.
Nobody is arguing that warrior dps isn't high. But there is more to this game than dps.
As others have mentioned, different classes have different strengths and weaknesses.
Warriors don't have full up-time on active mitigation like monks, druids, and DKs. We have no repositioning abilities like grips or knockbacks (Mekkatorque, M+). We have no self-healing, no immunities that would allow us to cheese mechanics (BoPing coin showers on Oppulence, removing ice block on Jaina, solotanking Bwonsamdi, resetting necrotic stacks in M+ etc.)
If dps was all that mattered, you'd be right and warriors would need a nerf. But as it turns out the other factors compensate for it and arguably even outweigh it since warriors are not the most played tank in mythic. They are middle of the pack at later bosses as well (close to paladins, behind DKs and monks) and those guilds usually have good options to use any tank class if they considered it stronger:
I also want to mention (as a bit of a side note) that 1-2k difference in dps (from the warcraftlogs statistics you linked earlier) is not really "a freaking mile".
The difference in dps between discipline priest and other healers is between 5k and 10k on single target fights. That one I consider problematic. 1k not so much.
There is much bigger difference than 1 or 2k even between dps specs and nobody would call BM hunters useless, they were still used on all fights by the top guilds.
https://www.warcraftlogs.com/zone/st...s/21#boss=2263