Why are people so critical when young people start non-profits?

Time and time again, I hear people say, "there are enough non-profits out there.  Young people should just join what's already out there.  I don't think starting another non-profit is the best use of resources.  I mean, I started my own, but…"

Starting a non-profit is hard.  It takes time, money and resources.  Starting a company is hard.  It takes time, money and resources.

When someone is thinking of starting a company, such as a new mobile app, no one ever says, "you should just join X mobile app company, you'll be able to make more of an impact that way".  Because it's not true.  So why do we say that to would-be non-profit founders?

There are many innovative, sustainably non-profit business models now that do good, while doing well.

Why can't we just accept that like in the capital marketplace, the best non-profits will survive, and the others won't.

The non-profit founders, the founders, the crazy ones - these are the people who are crazy enough to think they can change the world - but they need all the help they can get getting there.