Why Did Jim Carrey and Ewan McGregor Go Gay?

Regarding the flick I Love You Philip Morris: How come so many straight celebs play gay for pay? Aren't there any gay actors out there to fill these roles? ?Ricardo R., via...

Source: http://feeds.eonline.com/~r/eonline/answer/~3/oxe-cSmoCS8/b215717_why_did_jim_carrey_ewan_mcgregor_go_gay.html

Gretha Cavazzoni Gwen Stefani Halle Berry Hayden Panettiere Haylie Duff