With all due respect to the CFL, no American kid grows up dreaming of playing in the CFL. I'd suggest in most cases, they would barely know the league exists until they realize their NFL dream is dead.
The majority of American players come to the CFL because they have nowhere else to go but want to play professional football. Once they arrive and experience the game I would think their respect for the League would increase dramatically and many end up loving not only the 3 down football but also the country....they marry a Canadian girl and make a life north of the 49th.
It's no knock on the CFL, it's the nature of the beast. A parallel would be a Canadian kid playing pro hockey in Europe. It's not what he planned, and if he could make a NHL team he certainly would be playing in North America, but some are just not talented enough. They, like many US football players, make the decision that if they're going to play the sport they love and get paid for it, they may not be able to do it at home.