Having seen this exact same thing happen to fraternities before (although never this severe), the line "it's beneficial to everyone" is bullsh*t they use to cover their own butts. As pledges, you all will most likely be interviewed individually about what happened by University authorities, and you will have the chance to be honest. The responsibility and blame will be placed on the actives, NOT the pledges. If you do come forward to authorities, then don't tell anybody besides family you did so and try and keep it as anonymous as possible. If ROTC kicks you out or suspends your scholarship, don't tell anyone in the fraternity. You don't want to open yourself to retaliation of any kind.
As for the University dealing with 100s of kids getting high, that's true but you're not like other kids. As an example, for most kids an underage drinking ticket is a funny story and maybe a few hundred bucks. For a cadet or midshipman, it's probably gonna be a career ender.
I know this is hard and I'm really sorry what should have been a fun college experience ended like this. I was a pledge once too. I had to deal with hazing and the pledging process as well, but if what you are saying is true, this crosses the line into criminal behavior. These guys are not your "brothers." They're people with serious issues taking advantage of your willingness to deal with abuse for a chance to be a part of their organization.