Sure, and the off-campus lu*ury apartments include other things not in the dorms as well. We can debate what's a deal and what represents a good situation for a transitionary situation for young students, but the comparison at a base level for housing is still fair. I'd also say a place that doesn't kick you out (with no access) for a month and then again for 3 months represents an inconvenience that is worth discussing.
Minor quibble, but not all dorms kick you out (I lived in Centennial when I first came to the U, and I was permitted to stay). I didn't really care since I was going home. But being kicked out isn't really a
dorm thing per se, but a University of Minnesota policy. I spent my freshman year elsewhere and we were allowed to stay in our dorms over the break if we liked for a nominal fee. It was something like $50. It wasn't bad. At all.
The benefit of dorms being by semester also means that when summer comes around and you, as a student, want to vacate to your parents' house (as so many do), you don't have to deal with finding a sublet. You don't have to haul huge amount of furniture. And if you do want to stay in the area, there are endless Craigslist posts with students leaving for home or internship desperate to have you pay their rent during the summer.
For me as a non freshman coming to the U, I chose the dorms the first year because finding an apartment in what was the "big city" represented a daunting notion. Easing in, I had a building that I knew was safe, it was easily bundled into my student expenses, I had easy access to campus, and it gave me a year to figure out my surroundings and what was actually AROUND campus. Having a single in a quiet dorm didn't hurt, either. And in a way, it made me more of an urbanist. If I had lived off campus, I would almost certainly have had a car. With the U's parking lottery and high monthly fees, I decided against it and relied on bus, bike, and foot for a year. It was great as I learned a lot about the city and how to not be so dependent on my car.