It certainly tastes like tap water...

Having drunk from the fabled bottles in meetings at their offices, it certainly tastes more like tap water than anything else. The bottles do look cool though...

Anyway, Jonathan Bliss hits the nail on the head for me. They are deliberately an independent regulator, so the idea is that JH & crew won't be able to make them do what he wants. Whether or not this was the right decision, it does sound like Ofcom have ignored DCMS and acted independently.

As for capture by Sir Humphrey more generally, in the majority of cases it's not capture, but ministers realising that the things they promised in opposition are unworkable / impossible / illegal / downright stupid. That's not capture, that's the civil service doing their job.

If you want to see an interesting example of this, look into the detail of Vince Cable's comments on the graduate tax when he launched the new fee structure - once in government, and with access to government tax experts he realised that a graduate tax would be too easy to dodge and fiddle in practice, so he thought (rightly or wrongly) the new fee structure would be the next closest thing. Regardless of your views on paying for higher education, a hypothecated graduate tax cannot work within the confines of our tax and HE systems.