This is a bit arrogant and misguided. As another commenter pointed out, if you go to a hair dresser, you do get suggestions about what will look good on you, but the hair dresser won't refuse service if you go against the advice. As a developer, you can pick and choose your projects. If you don't want to work on ideas you think aren't good enough, cool; but don't make generalizations. Doing paid work for someone isn't the same as being a co-founder(as in investing or working for free).