SCCS is archaic, but VSS is much /worse/. It famously loses data, for a start (hence "Visual Source Unsafe"), and is fiendishly complicated despite being less powerful than CVS. The problem apparently is that all the important Microsoft projects did not use VSS, so there was no-one competent eating the dogfood to complain about the taste. As with most really awful Microsoft products it was bought from a 3rd party to fill a perceived gap in the product line, rather than being developed in-house by smart people who understood version control.
Inadvertently Microsoft actually created a scenario in which Windows developers were less likely to even have source control, because they might try VSS figuring it's the "obvious" choice to go with their other Microsoft tools, and after losing a week's work in one click they give up altogether.