I still stand by what I said. I truly believe that it is a risk (for their ruchnius) to be leaving their parents house. Aside from curfew, there is little supervision. No one overseeing where they are going, no one answer to. It is SO EASY to do whatever they want. Many would be afraid of doing those things at home, since they can risk ruining their name from being spotted. Don’t know about your particular school, but at mine, 2 people out of the entire grade stayed behind at the in town sem. The rest “had” to go to Israel. As for my Sem, I was very happy with it. And kudos to them for not even approaching the subject of kollel.
And btw, those yeshiva boys hanging out with girls- Those aren’t Israeli girls! They are American seminary girls. Don’t tell me that girls are so ‘innocent’. I don’t buy it. Even if they are not the majority and only fraction will fall, is it WORTH it?