I graduated with a CS major almost 20 years ago, and have been making my living since then as a programmer. I never learned anything about source control in collij. I learned it during collij, because I worked summers at a professional organization. I was lucky.

Most of my jobs have been in professional software development groups, where source control is as implicit as breathing. But for a few years I worked at a prestigious National Lab, and that was an eye opener. Much of the code I saw was written by scientists with no real-world experience. Nobody I worked with had ever heard of the concept of source control; they just sort of did occasional "cp foo.c foo-with-xyz.c" things. I set up CVS, explained the rationale, helped them learn it, and forced them to use it. Most appreciated it, because they could see how much it helped. They simply hadn't known. But... some resented it. "That's not the way we do things". (My wife still works at that Lab, also as a programmer, and says she sees the same thing). For the most part, the people who say that are stupid. Not 100%, since many have PhDs, but truly stupid nonetheless. And they know it, which scares them: they think if they use source control, others can touch their code and make it better, and they won't be needed any more. Job security through obscurity, perhaps.

Think about it: if you're competent, you use source control as much as possible: you know you'll screw up sometimes, you want a strong history of what changed when, and you want others to improve and maintain your code. But if you're not competent (or uncertain), you want others to have as little visibility as possible into your code and process.