Just looking at the WoW numbers, I believe that there are more people playing PC games than there were in the 1990s. Computers required more playing tweaking then to play games and internet was in its infancy so the mainstream really wasn't using them yet.
That said, the consoles have made it even easier to play video games and those games appeal to many more people. More people are gaming than ever before. The maximum number of PC gamers during any given year is less than the number of people playing console games today. Much less, especially with the Wii numbers added.
There were never enough hardcore PC gamers to compete with this console market, whether they stay or not.