The ASA is an trade org, not a quango.
Get it right, the ASA has nothing at all to do with the government, and by calling them quangocrats you are implying that they are an actual regulatory body.
The ASA is about as much governmental as the likes of the RIAA of BPI - the ASA lets people think it is a regulator (to stop people asking for a real regulator to be set up), but in reality it is a trade body designed to take heat away from its member companies, whilst giving off an air that it keeps adverts in check.
The advertising industry realises how much it is hated by anyone who isn't a worm in a suit, and this is how they play it - it gets called "self regulation".
It is why adverts either directly or indirectly promising unlimited broadband never went away - the market for advertising comms is huge, and the advertising industry wouldn't slaughter one of its biggest cash cows.