A better and more appropriate title for this list would be "Top 100 PC games of the last 10 years".
"Of ALL TIME" implies that "PC" means personal computers of ALL TIME - and that is more than just the latest batch of x86 family machines. I will date myself, but back in the day there were some AWESOME games on the Commodore 64, Atari 400/800, and Apple II platforms. Sure, technology has progressed and graphics capabilities have blown away machines of the past, but just eye candy alone does not make a great game. I actually lament the fact that so many "modern" games are really just tweaked variations of the 1st person shooter.
I remember games like M.U.L.E. (which if any top 100 of "all time" does not include somewhere it invalidates the list) , The EPYX Summer and Winter games series, Raid on Bungeling Bay, original Castle Wolfenstein, Wizardy (the first great dungeon crawl on IBM PCs) or ANY of the Infocom text adventures. Those were great not because of superb graphic eye candy. There were some great writing, game design, and mechanics in those innovative games.