In a lot of Twitter conversations I've had, people do use the like button as a kind of "I see and acknowledge your comment but don't have a follow-up".

But otherwise… yeah, a lot of the platform really does function as a sort of communal shouting-into-the-void, and the format makes it really touch (not impossible) to have long meaningful talks. More of an eternal bar-chat, where half the time you end up needing to shout to be overheard above the loud idiot two seats down.

I find it useful, and if the social bonds are a bit lightweight, I've still certainly forged some enduring relationships there. (Hell, I met my partner on there.) But it ain't Usenet. It ain't even G+.