My fundamental problem with Facebook

The fundamental problem I have with Facebook is that random people from my past keep "friending" me. People from high school, who I've not seen lo these twelve years and who (in some cases) I deliberately did not keep in touch with, continue to find me and friend me on Facebook. On the one hand, it's harmless. It's not as if these people are going to pressure me into reconnecting and establishing some meaningful relationship based on "remember when?". On the other hand, whaaa? How much time do these people have on their hands? Are they seriously trolling Facebook looking for people with whom they went to high school? Is it about collecting as many friends as possible on Facebook? If so, to what end? What's the point? If I haven't seen you, much less talked to you, in over a decade, pray why bother reconnecting on Facebook? It seems like an extended high school reunion (an event I've deliberately avoided). Isn't it awkward? Once you get beyond the basic update ("I'm now married/divorced/serially single, living in Houston/Canada/Uzbekistan, employed as a model/editor/brothel-keeper"), what is there to say? Or, to take another path, if I reject their "friending," am I committing some major faux pas? Is it high school all over again? If I'm missing something, please tell me.