Do you mean people who choose to make something "fun" with there lives, for example becoming professionnal dancers or guitarist, for example, are wrong? Wrong because they decide to have fun instead of carrying about bad injustices and all?
At some point I agree with you on that, we can't only care about that, but I don't belive it is a crime to try to enjoy life the best as we can since we can't force people to always live thinking of things going wrong around the world I mean... it's pretty depressing only thinking about that. If we can just find the right middle, think of others, and think of our own happiness, then that's healthy. I really don't think that spending all our time on trying to solve social problems is psychologically healthy.
Although, I really think people closing their eyes on what happens around them isn't good either... That's being selfish and unconcious.
I think we can enjoy dancing and music, and make those our priority in life (as career for example) even if it's only because it makes us happy, but we can't forget about injustice, inequality and other social problems.