Comment by Quarrel

While you're correct about Ofcom, the real distinction isn't really to the objective, but to the classification of its employees.

Ofcom, Gambling Commission, and the rest of the quangos are independent statutory bodies, and (this is a big distinction!) their employees are not civil servants.

Quangos include judicial tribunals and places like the BBC, or the Committee on Climate Change- it is a broad umbrella.