jdietrich argues:

"I think nearly all of these 'social' startups are bad news" (emphasis added).

This allows that some "social startups" might be a good idea, and is not (at least, not as I interpret it) an argument against social media in general. Besides, Facebook has long stopped being a "startup" so this comment does not apply to it.

As I understand it, jdietrich argues against the recent trend of "socialising" every aspect of our lives through increasingly frivolous apps that provide instant gratification but lead to shallow and superficial interactions.

This does not mean that you can't have meaningful interactions through social media. Your example of using Facebook to keep in touch with people when moving to a new city is an illustration of that. However it does not invalidate jdietrich's argument in any away.

It's "couldn't". "Could care less" is content-free, like "up to X or more". I could, or I couldn't. Whatever. "Couldn't care less", on the other hand, implies that your apathy has hit rock bottom, and there is no room for it to go any lower. "Could care less" is a mistake perpetuated by people who just repeat things that sound good without understanding them.