I don't think it's the developer's job to tell people how to live their life. If people enjoy apps like LikeSecret and they use it, then it's the developer's job to provide it. The problem OP has encountered isn't because he's targetting "immature introverts", it's because he hasn't figured out a good marketing strategy. The solution to that isn't to act morally superior and ditch the app, but to try out different strategies and see which one works best.