LinkedIn on the other hand is, depending on your point of view, either a database of incomplete, mostly outdated and uninteresting resumes, or a circle jerk of HR folks and dubious "coaches".
People stay on LinkedIn because they are afraid of missing out. But really, it's a genuine ghost town, a once promising service that was completely destroyed by their monetization needs and most of us have classified LinkedIn emails as spam long ago, after realizing you can't unsubscribe from it. And the only reason I haven't deleted my account yet is because once in a blue moon I get to take a look at forwarded profiles. You don't get anything interesting really, LinkedIn profiles are boring, superficial and generic, but hope never dies.
You can unsubscribe from all it.
This means that they can keep adding categories. For example I don't remember an option for receiving invitations for joining groups. If this option was available I would have disabled it and guess what, it's now enabled on my account.
But far more aggravating is that I'm receiving emails straight to my Inbox from HR people even though I unsubscribed from such email. Do you know how I know that LinkedIn has sold my email address against my preferences? It's because I'm using an unique email address just for LinkedIn.
You know, I can use a menu, I can find a link, have been doing it for quite some time ;-)
Big companies hate to be caught in the middle of controversies. LinkedIn's content is safe to a fault. Buying Twitter and making it uncontroversial would drain two-thirds of the value right away. Maybe more.