It's ok when Dj's change, even when it's not to your personal liking.
Only thing I don't like, is that it can affect your favourite style of music as well. This is the only negative thing I find about new styles and Dj's changing their musical preferance. In the end it can destroy certain sounds or diminish them. People who really loved that sound are forced to listen to stuff they like less, just because their real favorite music genre does not or barely exists anymore. In that case all arguments about if something is good or bad for a scene are invalid imo.
Luckily it's not at that point at the moment (yet?)