We certainly should push for better than what was delivered.
However, it is important not to conflate different things.
The vehicles/rolling stock here are perfectly capable of being speedy. It is a choice to operate them slowly. You can operate subways at different speeds too, Toronto runs subways in regular rather than high-rate motor operation which would provide more speed. We've also had issues w/extended or delayed door opening/closing times, particularly on Line 1.
Again, choices. Now there are reasons for said choices, its not just whimsy, but that doesn't mean the TTC got it right.
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In respect of Finch, we need to be clear, a subway was not ever going on this route. Period. So litigating that would be silly. The alternatives were 'Do nothing'; some variant of BRT, or simply a modified version of what was built.