Earlier quoted context omitted.
"I would use Linux only, but I like game X and Y." is incredibly common attitude among people who use dual boot. I'm not making this up, the phrase pops up very often on various forums, especially in context of linux ports for newly announced games. You don't see many complaints about GIMP being inadequate (and with the recent news that will be the end of GIMP complaints), or OpenOffice/LibreOffice incompatibility. Y…
I know many, many people that would never even consider switching to Linux until Office and the Adobe suite are first-class citizens. As happy as I am to see Steam come to Linux, I don't expect Linux to grow much desktop market share as a result. The future of user-facing Linux is Android.
I don't delude myself, though: several dozen percent games still won't show up on Linux. But it beats having to rely on the 5% games that are multiplatform.