I don't disagree with a lot of your points, and I agree that there is a stigma. 

I do think that we (and myself included in this) over-think what others are thinking about our own hobbies. It's no more 'geeky' than people playing Call of Duty or Warcraft online in my opinion.

I've got such a wide spectrum of friends, that I often find I have to keep myself to myself a bit when it comes to interests. There's a few that know what some of my hobbies are, others that know what others are, and so on!