So look, no one can make you share your work if you don't want to. I share bits and pieces of my work pretty regularly — I am notorious for dropping a paragraph of the day into a Gchat window — and I also have someone who reads my work on a daily basis, which is a great luxury to have. But I also have friends who will write for years and years, entire drafts of books, that they won't show to anyone at all, and if you ask them how they're doing, they'll just say vaguely that they're working. So everyone's got a different strategy.
I never share early drafts. I can't see the point. If I don't know what I want the writing to say, how could anyone else's input be relevant?
That's my take on it. For me, early drafts are discovery drafts.