No, they didn't went too far. In fact, I never understood why anyone would point out these features in the "GTA V sucks, GTA has gone foul" threads.
Social media? You're telling me that one site, which is completely optional to visit, where you can't do anything except read a couple of posts, has somehow changed the way you play this game? And you don't mind that in IV, social media (as in dating websites) have greater, actual influance on gameplay and are even being used in story missions?
OP: In Online, I don't mind being able to do everything through the phone, because multiplayer is not about interactions with NPC's, it's about interaction with other players. Why should I worry about driving to the bank to deposit my money when I receive invites to races or missions? Why should I waste time driving to Lamar to send a mugger after other player, when in the meantime that player can leave the game?
And the internet isn't more fleshed out than in IV. There's actually regression from rich websites, full of information about the in-game world to less content, but with a little more interactivity. And while in IV the internet is used to complete missions, in V you don't have to use it at all during the story.
The phone itself also plays smaller role in V than it's precedessor. In IV, you start side-missions with phone or computer, while in V you just go to the starting point. You can even hangout with friends without calling them, by meeting them in the world (at least the protagonists). In V you can't heal yourself, lose wanted level or get guns delivered to your location by calling a contact like you could in IV.