However, you're missing a point. If I sign up and pay for (say) 15Mb/sec service, and I'm trying to get a file from a server (or servers) that can feed it that fast to my ISP, then I should be able to get it that fast to my cable modem, dammit! Restrict my upload and download speeds at the rates advertised, impose capacity limits, these are fine. However, it is NOT up to the ISP to decide what I do within my limits.
In the days when ISPs were serving a few thousand dialup customers from a 15mbit ATM, maybe. Back then, it was possible to have full speed on all your lines without capping out your overall bandwidth.
But do you know how much it would cost Rogers if they had all of their customers (let's be conservative and say they only had 100,000 custoemrs). They're offering connections up to 50mbit. With 100,000 customers at 50mbit each, you're looking at 5 terabits of bandwidth that they'd need to purchase if they wanted to guarantee that all of their customers would have all of that 50mbit, at all times. While I don't have access to the pricing that tier 1 providers charge each other, I'd be willing to bet that the price per user would be well over the $150/month that Rogers charges for that 50mbit of bandwidth... we're still in an age where Tier 1 connection speeds are measured in gigabits and maybe tens of gigabits. A terabit connection isn't unthinkable, but it's still prohibitavely expensive.
Now let's be reasonable. Most of Rogers' high speed customers are on a 10mbit or 25mbit plan, but Rogers has a lot more than 100,000 cable subscriptions. They probably have that many subscriptions in the city of Ottawa alone, let alone larger cities like Toronto, and the rest of the country that they serve. If they're going to keep their costs reasonable, they're going to have to start cutting back on the amount of bandwidth that's available to you. There's an awful lot of math that's involved in figuring out how much bandwidth they can get away with buying in order to serve their customer base, but the short answer is that they're banking on the fact that most uses of network connectivity do not suck up full bandwidth 24/7, and the fact that their users will be connecting at different times of day. You may be paying for 15mbit, but honestly, you probably don't actually need more than 100kbit of that to surf to Slashdot, and that's only for a few seconds every time you click a link. They can provision you the 15mbit you're paying for when you do something like download a file from an FTP server (and for the most part, I do get that 10mbit I'm paying for... but only when I'm downloading from content networks optimized for the purpose, like akamai or youtube), but most of the time you're only going to actually be using a small fraction of that. On a smaller scale, this is why you can have 4 or 5 computer users all sharing a 10mbit connection via wifi, and they'll usually never notice the slowdown from sharing the bandwidth with each other.
Their issue with Bittorrent is that it breaks the pattern. People downloading torrents will use as much bandwidth as they can, constantly, and will often leave their systems on for prolonged periods of time. They feel they need to implement traffic shaping in order to ensure that the bandwidth is available for users who don't break the mold.
What the CRTC policy is saying is that Rogers should be buying as much bandwidth as they can get their hands on. They need to provision as much bandwidth as they can, and need to be a lot less conservative with those math algorithms they're using to figure out the minimum needed. But the CRTC is recognizing that it's not feasible for Rogers to buy up hundreds of terabits of bandwidth in order to provision full bandwidth for all users at all times, and that there will be times when traffic shaping is necessary in order to ensure quality of service for the bulk of their userbase. As such, the CRTC is saying to Rogers that they need to make public the policy of exactly what they're going to be shaping, and what times they're shaping it for. Rather than having a blanket "you can traffic shape 24/7" which is what Rogers is doing now, it's probably going to result in a "traffic shaping between 8am and 11pm, no shaping overnight" policy.
But it's completely unreasonable, and out of touch with reality, to expect that Rogers is going to provision that 15mbit to all of their users to be available 24/7. The cost per megabit to them is too high. If they were to allocate that kind of bandwidth, your monthly bill would increase significantly. Seeing as we're already overpaying for bandwidth as compared to Europe and Southeast Asia, that's seriously bad juju.