Well, that's your opinion (about it being the worst idea for Toronto) - not a fact. Maybe I think Transit City, putting surface Light Rail everywhere was the worst idea for Toronto? (I don't, for what it's worth, but I also don't think it would have been the
ideal choice for Toronto, or any major city). Just like any transportation solution out there, there are good implementations, and bad implementations. Monorail has the unfortunate problem that with fewer installations, it's easier to target those that haven't worked out very well.
Try this thought experiment. Zoom out and pretend that no city in the world has any kind of mass transportation system. You don't know what a train is. A city presents two options to its citizens:
- We could build trains above the city streets, with a narrow, clean beam, small supporting columns that only involve boring a hole the size of a trash can, trains would glide silently overhead on rubber tires, and offer passengers a view of the areas they're passing over, so they get their bearings of where they are and can enjoy the view. Stations are bright and airy, making people feel safe.
- We could build trains below the streets, which will involve ripping up neighbourhoods, roads, existing infrastructure. They'll also make a ton of noise when they're above ground, because we'll put steel wheels on steel rails - and the rails will just be supported on a bunch of rocks that hopefully won't slip out of the way. And since it's in a dark tunnel, people have no idea where they are and have to guess by station names only where to get off. The dark, dirty tunnels will also offer a safe haven for crime.
Doesn't it kind of seem obvious that elevated/above grade is
always a preferable choice?
There are some valid arguments in this thread; one that I see coming up a lot is the choice of a proprietary system causing trouble for future rolling stock purchases. But I have to point out that no matter what system you're using, rolling stock is always customized. Do you think you could put one of DC Metro's ROHR trains on Toronto's network and it would just work? Or Put NYC's trains on Chicago's cta track? Of course not. Besides gauge differences, there's the train width, the current collector location, the control and communication system... there are a host of issues that would have to be resolved for it to work. Every train order is always "custom", no matter what the system. If Scomi and Bombardier both decided they didn't want to do it anymore, I'm sure Hitachi would step up and build trains for Saõ Paulo. It's a myth that only monorails suffer from this - it's just more obvious to the layman that there are vendor issues when it's very obvious that the track between different types of monorails is different. The track, power supply and control systems on
every urban rail system are different.