I went to an excellent university on a full ride, same size school as USNA. My roommates did go to keg parties. That was their choice, fine by me. I never studied in my room, as that was for socializing. I was required to maintain a 3.75 to retain the tuition part of my scholarship, so I kept to the straight and narrow, found plenty of like-minded people to be with. We had our fun, but priorities were focused on graduation and staying out of trouble. I started dating an AROTC guy junior year, liked how disciplined and organized he and his ROTC friends were, how they had goals, plans and a known career after graduation. I was ripe for the Navy officer recruiters, had the requisite grades and well-rounded profile, no troublesome incidents, and off I went to OCS.
The point is... ROTC is a superb Plan B, and is often a better fit than a SA for some. If an ROTC mid or cadet has their priorities straight, they will make wise choices in friends and actions. There are all kinds of people to hang out with at college or a service academy, and it's a simple matter of avoidance of other social groups if they are bothersome. And yep, there are plenty of roommates at the Service Academies who manage to go to keggers, underage too, though admittedly at more restricted times and with higher penalties, and lead a "party life." SA mids and cadets are not perfect, and while generally all-around good "kids," they have feet of clay and make their share of bad choices.
Amongst our USNA sponsor plebes, there are always a few each year who are shocked by some of the behaviors they see in Bancroft Hall, having believed that all mids were just like the official Admissions videos. Yes, mids come back drunk and throw up in awkward places, roommates don't respect others and sneak in the mid GF or BF for "activity," do clique-ish things, gossip, hide contraband in the room or do things and expect the roommate to tolerate it. Not all, not all the time, but enough to demonstrate their humanity. It's a great reality laboratory for learning how to handle inter-personal relationships and gaining social skills that will help them in close quarters on ships, subs, planes and the battlefield.
Lots of other excellent points made by posters - the more research and information, the better.