But a different pronunciation of the consonants is part of a regional accent
You can't ask for a regional accent and then expect just different vowels and not different consonants
I come from a part of the country where there are practically more accents than people. I am well aware of the nuances of accents, with respect to pronunciation. If you want to attempt to defend the pronunciation of "3" as "free" and somehow legitimise it, you are quite entitled to do so. I - and many others I suspect - would strongly disagree with you. Some of us find it particularly objectionable in the context of a broadcast announcer role on a major BBC channel - for reasons which I would think are pretty obvious to most people.
I'm not saying that an announcer for the BBC should do that (of course accent should be a bit clear(er) for that), but one definitely cannot say that a different pronunciation of the consonants is part of a
bad diction
, as you were implying
I implied no such thing. I have been very clear about the distinction between accent variations and good pronunciation. All accents produce variations in pronunciation - that's basically what an accent is. However - particularly where a professional broadcast announcer/voiceover role is concerned - there's an acceptable threshold of variation, where the pronunciation has not changed significantly enough: to cause the listener not to recognise the word at all; for the word to sound like a completely different word; to cause the meaning to change.
I've heard plenty of people with the same general accent as this particular announcer and they manage to pronounce these words in a manner which is recognisable. When words become different words or sounds that are not actually words, then we have a problem.
The examples cited in the Points of View piece were:
"Thunderball" became "Funderball"
"Thirty-Three" became "Firty-Free"
"Thousand" became "Fousand"
"Thriller" became "Friller"
"BBC Three" became "BBC Free"
"Radio Three" became "Radio Free"
This is not acceptable pronunciation for a professional broadcast announcer role. The defence put up by that BBC spokesperson was utter twaddle.