I think it is wrong to except everyone to contribute to open-source and I have seen that even the very smart programmers are not interested in making personal projects or contributing to existing ones.

Honestly, after mind-taxing eight hour job, you want to go home, watch a movie, read a book or some other relaxing activity. Not to mention that for people with families, it is nearly impossible to find the time to contribute. The rockstar-ninjas with thousand-starred repos on Github are very rare.