Sorry, I was trying to characterize the sort of argument given: "Just don't use it" only works if the people you want to interact with are available some other way in a nearly equivalent fashion: if one's friend group is mostly on Facebook, you sort of have to pick between using FB and missing out on a certain set of social interactions.

Oh, then I agree, but I would suggest it's a worthwhile inconvenience. The more people quit these services, the less incentive other users will have to remain. It's surprising sometimes how even one person's decision can generate mimicry.