half the job
The BBC don't need a regulator just to protect themselves from themselves, they need one to protect them from unfair external interference as well. Particularly unwarranted political pressure and the nonstop lies spouted by some media rivals. OFCOM in that role makes no sense at all unless the aim is destroying any independence the BBC still has.
Enough people hate them for usually purely selfish reasons, OFCOM aren't the solution to ensuring honest and strong but fair and balanced independence in the face of so many wanting to cripple and control the BBC.