I didn't say they can't. But the guys you mentioned showed clear signs of wanting to lead right from the start. Zuckerberg and Gates in particular started off with big egos, big ambitions and a clear desire to spearhead a technological vision. Again, I don't know the Reddit team, but have you seen any of their developers taking any kind of leadship initiative?

i think they did a pretty good job increasing the monthly page views to 1.6 billion..

That is not an example of a developer taking leadership initiative.