We have Rogers listed as a Canadian carrier. You can see that in our Carrier page.
Or do you mean why Rogers has not been listed as a Canadian carrier offering the Apple iPhone 4S? If that's what you meant, we thank you for reminding us. We just added Rogers ^_^
Here's their 3 Year Contract Pricing for the iPhone 4S:
16GB – $159
32GB – $269
64GB – $369