They couldn't air music as it would be in "competition" with MuchMusic. And of course we can never have competition in our anti-capitialist TV industry.
Anyways the US version of MTV doesn't air much music (notice the pun) either except for premiers or hit videos. The music airs on MTV2 in the USA.
We need a whole transformation of the MTV, Much Music thing up here. With some VH1 and MTV 2 maybe...