I don't think it's fair to judge a candidate based on their online presence. Some people are very private, or for whatever reasons prefer not to have an online presence.

Furthermore, if you judge every candidate by the number of linkedin posts and stackoverflow answers or whatever superficial metric than you will miss out on a lot of talented people.

I'm not the type who has an urge to express my opinion or feelings on anything. I've been on Youtube for years and never posted even one comment. Although I always like videos, if I liked them of course.