Toronto has only so many billions lying around. If Toronto puts itself on the hook for 30 years of property tax hikes (which still doesn't cover city's share), in order to build huge capacity, where it is unneeded, it will have less financial leverage to add capacity where it is desperately needed.
Tory's vote buying plan, adds another $2.5 billion (his estimate) in debt, in order to alter Provincial RER plans, by taking the line west along the formerly vacant Richview corridor. The debt and TIF role, would require changes to Provincial legislation, and can only be considered 'financially responsible' in the wake of a Ford mayoralty.
This logic would work if there existed a constant revenue stream for transit expansion.
In practice, revenues are getting allocated on case-by-case basis. If Scarborough subway is cancelled, then the city's portion will not automatically get allocated to another transit project. Most likely, it will be simply cancelled.
Moreover, the whole process (lots of noise about switching to subway, then apparent consensus of the 3 levels of government, and finally going back) will create a lot of resentment in Scarborough. Next time you ask for a property surtax to support DRL, or another project elsewhere in the city, you will see those Scarberians writing to their councillors to turn down any tax increases.
On the other hand, if Scarborough subway is built based on those property surtax money, that sets a good precedent. The same model can be used for other transit projects, including DRL. The absolute amount of surtax is not that big, in the range of $30 to $100 per year per household for most of residents. Hence, it does not preclude funding other projects.
If we vote for unrealistic promises, we are rewarding politicians who lie.
The truth is that a project this costly needs to be funded by higher levels of government. The city can cheerlead, it can offer money & persuasion, but the Province is likely to propose the timeline. Even if a Toronto politician were to tell you otherwise, complex subways require a time consuming EA, procurement contracts, maybe even an AFP. I would not expect to see any real construction progress in the next 4 years on it or any other unapproved subway.
I am not blaming Chow for not promising to build DRL in 4 years. Obviously, that is not doable.
All I am saying is that Chow is not a strong proponent of DRL, rather a casual supporter. Tory is not a strong opponent of DRL, rather a casual defector who might come back to DRL if his SmartTrack plan does not work out as expected. Therefore, I am not going to take their position on DRL as the main reason to chose between the two.
Although, if their positions on all issues other than DRL were identical, I would chose Chow, as currently she is more supportive of DRL.