It's a lot easier to just leave when the semester is almost over, you find out your roommate was maybe pocketing your rent, and the landlord shows up and says "I don't want to rent to singles any more. I've got a family moving in on Monday." That one had ripple effects in my life for years even with the highly undesirable safety net of moving in with family on short notice.
I also know how much damage a bad tenant can do to a property -- graffiti, smoke damage, pet stains -- on top of not paying rent.
I can see why people get pretty heated about tenants' rights, but I've also seen how badly both sides of the transaction can behave. Sometimes eviction is the best course of action for both parties.