First of all a majority of the posts in this thread are completely ignorant.
Secondly the number one reason there is no NFL team in Toronto is:
Buffalo is a small market team and 10% to 15% of their stadium fans come from Southern Ontario. IF those fans had their own team, the Bills, a flagship AFL frnachise would be in even more dire straits then they already are.
The Bills moving to Toronto would be interesting. Toronto would be the fourth largest market if it was an American city so it could certainly support an NFL team.