Why did Wil put his wife on the other team for Geek Out!? Because that way, no matter what happened, a Wheaton would be on the winning team.
This bit from Dragon Age:
Sam: Let's make sure we don't go back to the Fade in this damn thing. What if it goes back? Wil: If we are destined to go to the Fade, to the Fade we shall go. Chris: [instantly] Fuck yourself! Sam: Yeah, Jesus! I'm not going to the Fade! Kevin: Yeah seriously, fuck you.
In context, Chris' character, Fonzor, is a circle mage. Considering that all mages must go through "The Harrowing", which means going to the Fade and resisting attempts at possession by the resident demons, it wasn't in Fonzor's best interest to go back to the Fade.
Additionally, Wil's character was a dwarf. Within the Dragon Age canon, dwarves do not dream, cannot become mages and, as a result, have the least experience of the fade. Every non-dwarf in the group has an entirely different reaction to the fade than him as they are more likely to know how dangerous it is.
On a more meta level, the segment of Dragon Age: Origins set in the Fade is generally regarded as That One Level, and many players would react the same way to the suggestion that they go through it again.