I think that the thought of taking subways to the downtown should be scrapped. We need other kinds of routes. These routes only serve to take people to downtown and back, for the most part... why? Because the auto-industry is always opposed to things that can challenge the dominance of their precious auto's. Hence, we need to provide real alternatives to the automobile, by having an eglinton metro and a full sheppard metro.
I agree that we shouldn't just build a network that assumes that everyone needs to go downtown. However, the point of transit is to take people where they want to go, and a lot of people do want to go downtown, judging by the congestion on the southern portion of the Yonge line. We might as well give them an alternative, which would increase ridership by reducing crowding and bringing more subway stations closer to people. By doing so, we would be providing a real alternative to the car.
Downtown is where they need transit improvement the most. Their streets have way less capacity than suburban streets, yet they have way more people living or working near them. Obviously the difference has to be made up in alternate modes of transportation. A line built downtown would have much higher ridership and therefore profitability than in the suburbs, because there are more people around to take the line and the car is much less competitive.
When you have the thing built the benefits of it are good. Such speed for long distances is absolutely vital to enhance livability in the city. That is what differentiates toronto from top notch cities in the world. You take madrid, london, berlin, moscow, tokyo, paris, or others... they have outstanding metro systems. Huge outstanding systems. You can go pretty much anywhere with them. Life there is better, thanks in part to the rapid transit that is continually being expanded.
That is something I have thought about too. When the TTC decided the technology for the Eglinton line, they did so using ridership projections. This is essentially deciding what the bare minimum they can spend while still satisfying the demand. Nowhere in this process does it take into account the benefits of Subway vs LRT, or the fact that more people would take a subway than would take an LRT (particularily people transferring from other surface routes). When Hamilton was deciding whether to build BRT or LRT, they decided that both would satisfy the demand and LRT would cost more, but LRT would have more benefits, so they chose that.
That said, I still think that LRT is the way to go for Sheppard, just not the way the TTC is doing it. They need make it faster by decreasing the number of stops and if that means they have to run a parallel local bus route, then so be it. They need to stop trying to make the LRT an improvement on the 85 Sheppard East and aim at improving upon the 190 Scarborough Centre Rocket instead.
The Hamilton report is here:
http://www.metrolinx.com/Docs/Agendas/Feb19_10/Hamilton_BCA_FNL_DRAFT.pdf
For an explanation of TTC's decision on technologies, see question 5 of the FAQ here:
http://www.toronto.ca/involved/projects/eglinton_crosstown_lrt/pdf/faq.pdf