If YC were a non-profit, they definitely wouldn't have been able to raise money from LP's to scale the program, and would therefore been able to accept far fewer teams than they do now, certainly not everyone!

I agree that there's nothing wrong with wanting to make money AND help people, but I also want to add that strictly maximizing the positive impact does not mean strictly minimizing making money either, sometimes making money enables you to help a lot more people too...