why don't they use real currency in video games?

[Duke.Togo]

Wait a minute... are you saying I can't transfer all that Gil into my 401(k)?

[gbpxl]

I was more talking about simulation games than anything else- I understand why octoroks aren't shitting out hundred dollar bills when they die.

I know that Roller Coaster Tycoon used real currency. I can't imagine the same thrill of that game would be there if I was earning "credits" or "bells"