I agree, it's not solely incompetence. The yellow cards given to Rice and Trossard earlier in the season in decisions that haven't been repeated weren't incompetent, they were pointed and deliberate.
The smoking gun that would destroy PGMOL would be if it ever came out they'd ever experimented with controversial decisions to "drive engagement" ... I consider it a bit less likely than basic bitch vendettas and meddling, but not impossible.