That PC's are in the majority is not very strange seeing the background of this community. Don't understand the link with serious racing though as our console leagues are taken very seriously.
Yes I know everyone here is very serious, even on consoles - I've seen the 360 F1 threads It's just that most sim-type games are unfortunately on PC. I bet you if rFactor 1/Race/GTR etc. was available on consoles, and as easily-moddable, the numbers would be considerably more even. It's just a result of that, not the platform itself causing it.
While the majority of my racing games are for the PC, I must say one of most fun and most enjoyable is F1-2009 for the Wii.