I agree. It's been a few years since I've lived in a dorm, but this leads me to wonder...did they take the locks off of the doors since I left? Seriously, who leaves the door unlocked to take a shower, go to class, or...EVER? Who leaves valuables lying around unattended in libraries and student unions? And honestly, I think your textbooks are more likely to disappear than your laptop, especially around book buy-back time (easier to get away with, too). If you're smart enough to be in college, you should be smart enough to properly care for and look after your things. Just MHO.
If you leave your laptop unattended in public, lock or no lock, you're just begging for it to be stolen! Take it with you!