Well, I wrote this before and I will write is again. It is simple economics. Vast majority of Videotron TV customers are francophones. Unlike mobile, telephony or internet, the TV customer base is very much demographic-driven. Increasing service means more investment and more cost. I think Videotron's calculation is that the increase of revenue by adding HD channels is still below the increase of cost. Also, they are enjoying almost monopoly in cable services, even if Bell is slowly chipping on that monopoly.
All in all, I am quite certain that for Videotron, at least for the time being, the status quo is the most profitable state for them. So hey, if it ain't broke, why fix it?
Regarding the billing, one pet peeve of mine was that Videotron did not want to give me my bill in English. I asked them several times, each time with the answer that the next month's would be in English but never was. I grew tired of asking and just letting it be, until I moved.