The pressure of participation

In the internet, the social network Facebook is in a phase of downsizing by its users (unwillingly). I read of many reasons but one I don’t read, the main problem of this kind of virtual social network.
A real physical social network has the same problem but it is not as severe caused by the real life nature of the non-virtual form of a social network. As a member of any social network your participation demonstrates a certain degree of commitment. By the nature of us humans as social beings we need to re-confirm our commitment continuously to be an accepted member. Every member demonstrates his or her own level of commitment. Real life leaves spaces for a lot of reasons to justify that. A virtual network has much less options. The implementation does not allow a natural own driven fluctuation of the own commitment. In real life many different things allow us to step down and do less socialization to a group or single member of a social network. Facebook does know the soft way. I want to disconnect to a member. How do I do it in real life? We learn in the course of our youth how to put more space between you and somebody else without a declared verbally expressed reason; and this without raising questions of other(s) or hurting somebody.
Facebook is cool and hip but to implement real life like circumstances which allow to socialize in a way of not feeling pressure is really hard and controversial. It is just not mature enough. How are people dealing with this? Deleting the Facebook account fully. This is a last option caused by just not enough reality in this virtual social network.

PS: In case you wonder why I did not agree to your Facebook or MySpace connection (even though I already got a few connections)? Certainly not because I don’t like you or don’t want to publicly show my relationship as friend.