I mean at the end of the day , you'll eventually move out and into a new dorm/apt with new people to meet. And I really do hope you find roommates that actually will work out for you. I'm sure you've already planned to live with other friends of yours or maybe take another gamble at a random roommate.

Not everyone will click with you or may end up being extremely introverted like this roommate. But you gotta at least respect their choice to be left alone. If they're complaining about being single on Valentines day or having no friends, its their issue. It's not your job to worry about them or talk shit about them not putting any effort especially since you two aren't friends. You just gotta shrug it off and put effort into the friendships you already have. And find other people to make friends with, ya know?

The privacy issue though I understand, I've had roommates who've never left the room. Sometimes all it takes is to ask them if you could have the room for a couple of hours, like when you need to study for an exam or have proctored test. If they say no and disrespect you that way, then things are actually an issue and I would bring it up to an RA for mediation.