Those who are in charge of the mosque are falling short in their religious commitment; should he stop praying there?

Praise be to Allah.

You have to continue going to the mosque, and beware of causing division in the jamaa’ah of the mosque. Try to reform it from within, by preaching, advising sincerely and maintaining good relations without doing anything that is haraam. Perhaps if you submit suggestions written in a gentle and kind manner, this will help to improve the situation. Be optimistic, for things may be better in the future. This committee or some of its members may change and become more religiously committed and better; you may even be one of them. We ask Allaah to give you and us strength.