This is a inevitable result of the conflict between the gentrification of this area (this is now a very expensive part of London to live in); and the areas traditional "bohemian" image, even though that now seems to be largely a commodified tourist attraction.

I think that the rise of the amplified busker has probably also been a factor, and to be honest I think there do need to be some restriction on this. Sometimes there is what amounts to a full amplified band, with a drummer playing near the tube station that can be heard a considerable distance away. Unfortunately I think this has led to a sort of speaker arms race among buskers so that amplification becomes the norm, and also led to quieter buskers also being tarred with the same brush.