I don't understand why you think that even in a place where lots of people care about culture one can simply decide to play at a concert whenever they want, especially if they are still students. And he specifically says he's busking as an alternative to practicing at home, not as an alternative to playing at a concert.
In my limited experience, places where there is more interest in erudite music also have more people busking, not less, since there are more players overall.
In my limited experience, places where there is more interest in erudite music also have more people busking, not less, since there are more players overall.