Whether or not I stop to listen to a busker has as much to do with the situation/setting as the music. If I am on the London Tube I am not likely to stop because its an unpleasant space. If I am walking through Central Park, around St Remy or Venice (three of my best busker moments) or in general on holiday I am more likely to stop. I am not looking for great musicianship, I am looking for great music selection in a pleasant setting. I can say the same about golf. Only once in a while do I come across an exceptional course virtually by accident, but more importantly, I come across many good courses which are a pleasant if in no way an exceptional day out. Arguably, and like buskers, these courses can be just as enjoyable as the famous counterparts. Finally, the fantastic thing is, and again like buskers, is it doesn't cost much to have a look.
Ciao