Thinking about social media/online communities and "real" people

I was talking to someone recently about online communities - social webbing stuff, and was surprised to find out that although there are still a lot of people that don't do Facebook, Xing, LinkedIn, etc. for whatever reason, (and there are still many folks that just downright don't want to), but also because I found out that there are many people that don't know "how" to (and I am speaking of tech-saavy folks here). This response sparked my interest, so I did a bit of informal market research and asked around ... I wanted to hear who "did" social webbing, and if not, why not.
It seems the main issue most folks I asked have, is: "why should I?". Like: Why should I write a blog? or: "Why should I want to put up a list of my favorite music onto a social website?" or: "Who could be interested what I have to say about that?", or: "Why would I want to put up pictures of my hike with my dog for total strangers to see?" etc.etc. There were quite a few more questions like that, but this kind of sums it up.
The other subject that came up during these discussions were: "doesn't that take up a lot of time?"; and comments like: "If my staff were doing this stuff during work hours, we'd never get anything done"; and some tough things to consider, like: "what if what I post there backfires on me/my company? What happens then?"
These questions certainly have their legitimacy. There are plenty more considerations that need to be given their due respect as well: like what if you are on Facebook and your worst performing staff member wants to hook up with you "as a friend" and give you, the boss, a gold star for being such a "cool friend". Egad!! Many of these thoughts would probably not merit a sweat for the kids that use these social webbing sites today, geezz - they grew up with the Internet and they know how these things work - but that is a totally different story if we're talking about people in business using these tools - especially in an environment that is not familiar with the culture of social webbing platforms.
I will follow the development of how these near-Best-Agers that I talked to, decide to handle this: on the one hand, they want to join in on the fun - on the other, they are wary of the consequences their joining in on the fun could have on them.