Well, in fairness, we don't tend to hear much from the other sports, but I suspect that it has to be pretty horrendous for anybody to take notice of a Womens Field Hockey player getting suspended for the same things. I also doubt that its really any worse than it ever was, just more public.
No, they don't need babysitters. They are legally adults, and they need to learn to make good decisions, and take responsibility for the consequences. This is part of the process. There is a lot of scrutiny at the moment (and that's easy to understand) but to some extant that's making it look worse than it is. And I'm not suggesting that its not bad, just that added scrutiny brings to light more details making it look worse.
I don't know why these 9 were suspended, there are no details on that. Green and Griffith's suspensions are more than likely due to their off season arrests, but I have no details on the others. They could be suspensions for transgressions such as cutting classes, missing workouts, etc. Or they could be for much more serious violations. We'll probably never know, but I wouldn't let my mind run too wild with the idea that these were all legal issues.
In the end, you make rules, establish penalties, and discipline as needed under those rules. The players ultimately make their own decisions. Its not much different than as your own kids become teenagers, at some point, no matter how you raised them, they are going to make their own decisions, and their not always going to be in line with how Mom and Dad raised them.