US selective service

I wasn't even aware of the selective service until I became an adult and learned that men over 18 had to sign up for it or they would not be allowed to have student loans for school. It's pretty much a draft list to serve in the military if needed. I found this awful that they make young men do this in order to get education(but of course excludes the rich). I'm not super informed on this subject so if you have any different/additional information it's welcome.

Do you think this is okay for the government to implement or is it wrong?