There was only a single semester when I *needed* the computer lab, and that was the first I had moved off campus. I didn't want to shell out the cash for internet access because, lets face it, I would spend so much time in the CS lab anyway.
The CS lab was linked directly with the department file server, and I had been running linux full time since my sophomore year. As long as I had enough bandwidth to upload a source file, or download the occasional lib file the prof provided, there was no need for me to be in that lab, and on campus bandwidth was plentiful.
So why do it? I liked the company. I didn't like everyone in that department, to be sure, but most of the folks I knew were pretty good guys (and a couple girls), and it was fun swapping stories of funky things we were experiencing on our own systems, problems we were having with our current projects, or the latest interesting story on Slashdot.
I was a TA for most of my college career, but I spent so much time in the lab that the idea of logging my hours was really a joke. I think it was true for just about every one of the upperclassmen (and those who knew what they were doing) that we were always there to help out anyone who asked.
There was a lot to be gained from that experience. The CS lab was a space where we could work with others, where we could serve as mentors, and where we could get a feel for what it might possibly like to work in a room full of other people with a common interest. I shudder to think of what my CS experience would have been like without that space.