For many projects, version control software is viewed as "overhead." The bottom line is "the bottom line:" large projects will save money by using something that is popular, which in turn requires less re/training of staff, results in more familiarity with industry standards, and generally gets the job done with the least amount of fuss. Since money is core to the project, and no contract I'm aware of ever paid anyone per checkin, projects will go with what works. For about 90% of the industry, it's CVS.
Counterexample in point - a spacecraft control center project I worked on years ago was using a large, very expensive commercial version control system. The approximately 100 developers were having such difficulties with getting versioning to work and got so wrapped up in build environment issues that the project manager declared a halt of development and decreed a "Makefile Day." The festivities of Makefile Day had a core of 5 top-notch developers visit every development subgroup to help fix their makefiles to work with the versioning system. The cost to correct these problems was 100 developer days (Apologies to Frederick Brooks.)
If you are a new software developer and either work in the industry, or are looking to get into the industry, you are well advised to learn CVS. To the more seasoned developers thinking of changing to different control systems, I ask this: when have you gotten around to learning emacs so you can stop using VI? What's that, no time to relearn, what you're using works fine already? What about your neighbor? Precisely my point.
I have to agree with the first post - the "Troll" points out that the author recommends against CVS, but neither adequately supports that assertion, nor provides a recommended alternative.
Remember, for large projects, you have to use what the project is using. For managers, you must use what a bulk of your developers are familiar with, or what a bulk of your soon-to-be-hired developers are likely to be familiar with, or incur high overhead costs. For small projects, it doesn't much matter, but realize that any VCS is better than no VCS.