To be honest, the weakest link in the chain is you. The primary determinant of how many friends you have and how social you will be in university is yourself. If you put yourself out there, join clubs, make effort to follow things up with people, you will have friends.
I get the broadness. It has upsides though. In a tiny course, if you fuck up, everyone knows. If there are people you don't like, they'll be everywhere. In a pool of 100 people, there might not be any that share your uncommon interest.
Now imagine you have a pool of 1000 people. It didn't work out with this person? 999 more to choose from. Had an argument? Probably will never see them again even if you tried. Out of such a huge pool, there's bound to people who like X just as you do too. Granted, its less like highschool in how it forces you to make friends but there are distinct advantages, it's not all bad.
I dont know if this is just me but 99% of the people i've "met" in my course i never talk to after the semester ends. Your common thread tying you together is that subject (unless you make it otherwise). Once that goes away, it all goes away. Joining clubs are far easier and better ways to meet people if you're looking to be social.