i think it's who you tell your criticism to. if you are polite during a concert, but didn't feel what others did you don't have to fake liking it. i always clap, but don't always stand up for an ovation (even if lots of others are) if i don't agree. you don't have to be rude and shout 'terrible, terrible.' i usually share witha good friend after driving away from the concert. i wouldn't want people commenting directly on my playing right after concert if i was a concert pianist (which i hope to become someday). unless, of course, it was something good. pianists should get applause at least for the effort they put in.
you know, the deeper you get into music, the more you know exactly what you like and want from an interpretation. i was listening to leon fletcher (is that how you spell?) and he was playing the last mov't of the emperor concerto. i thought, this is too dance-like, fast, and not serious enough for me. but, for someone else, they may think it's grand. usually, the criticism is according to tastes and not out and out BAD. the higher the quality of pianist, probably the less 'risks' they take in interpretation, imo. i tend to like guarded interpretations rather than flamboyant. anyone can impress an audience, but not everyone can impress music critics.
be one. but, be polite. and, if you are playing something that has a serious quality, keep the tempo from racing. it destroys any sense of nobility.
Topic: Critics.