No, and I think the main reason for this is the “prestige non-rhotacism” of British Received Pronunciation.
You know how typically in American accents you can always hear the “r” sound? Well that's rhoticism, and it's perhaps the difference between British and American accents that most stands out.
One of the things that really gets up our noses is “Americanisms”. In Victorian times we would play fast and loose with our own language to our heart's content, but with the old order upended a large number of these innovations started to come from the wrong side of the Atlantic, and so to preserve our Britishness it is now our duty to identify and reject all such dilutions of our pure language. After all, it's called English so it must be ours!
I have a Canadian accent but live in London. Most people I meet assume I’m American. Those that guess that I’m Canadian often say that my accent is softer that an American accent. I suspect that this means that they find American accents harsh, and Canadian accents a bit less harsh. They certainly don’t consider them refined.
I don’t know what you mean by refined. However, I do like American accents and generally prefer listening to them than to many British accents which can sound so dull.
I grew up in south east England and the typical middle class accent spoken there sounds really whiny and uninteresting to me. I’ve had friends from various places in the US with different accents and most films, videos and tv shows I watch involve Americans. I don’t think of American accents as being in any way exotic.
I like the fact that an American is judged more by the words he speaks than the accent with which he speaks them. In Britain politics, theatre and cinema, along with all manner of powerful positions are filled with bumbling toffs talking nonsense with posh, “refined” accents. The only reason many got where they did is because they come from a wealthy or aristocratic background. Success due to background is not limited to the UK, but I always liked the fact that the President of the USA will speak in the same way as most people from the same area, rich or poor. Bill Clinton’s Arkansas southern accent is a modern example of this.
Listen to the words, not the accent. Then you will truly understand how refined the orator is.