PhilR:
In general it's worth giving TV presenters the benefit of the doubt, as in many cases they're paid talking machines. They bear a much-reduced responsibility for what they're saying than, say, a politician.
I don't think that I could have written a more damning verdict on the Beeb and its benighted presenters than you have. You paint a picture of a bureaucratic agenda bound monster that had failed before it even began the River Pageant OB. There is a well worn cliche regarding RAF Officers' Annual Assessments that goes:
"This officer sets himself abysmally low standards and consistently fails to attain them"
That is where we seem to be with BBC OBs, where "Celebrity" presenters who know little and say even less that is worthwhile are forever being cut to, and hence away from the subject of the broadcast, to stick a microphone under someone's nose and ask them what they think of it so far. The Beeb, like most other institutions that were named "British" something or other, is too big and too remote from the real world. Cocooned in a safe assured state of guaranteed survival they have lost their way. The need to be shown it, ie the way out. It is no longer the colossus it was, rather it is a shambling muttering old has been. Time to remove the life support!