I remember having such problems when in university. There were basically two reasons:

1. You always end up with someone too lazy to set-up their development environment correctly and refusing to check-in their code. It breaks the dynamic for everyone else. The cure to this one was to never work with them again.
2. The university did not provide a location for repositories and it had to be figured out every time. We first had to select a location, then a VCS to use. Some students had servers, others had preferences. For small projects, setting up version control took more time than actually doing the project.

This should partially be resolved now with DVCS. You can start locally and simply push to any server where you have shell access, and move around as needed. No need for anything to be installed on the server.

By the time I was out, they did set-up a central location after years of requests.