Those aren’t big players on a global basis. Canada is concerned its culture is at risk from globalisation, and those concerns are not without merit.
I don't think that preserving Canadian culture is a factor in any of this, nor does it seem to be a concern of the current government.
These same politicians have been bringing in an absolutely staggering number of foreigners each year for many years now, with most of them from cultures that are extremely dissimilar from, if not outright incompatible with, what was Canadian culture.
Yet the government is passing even more laws to try to give them cash grabs. These companies should be broken apart and the spectrum sold off to smaller players. Canadians need more competition in both media and wireless / internet access, not less.