You are assuming that upon extending the line, there won't be further densification of the areas around the stations; nor will the ridership feeding into these stations increase simply due to the growth of the region itself. That's obviously a faulty assumption. Given the impact of said ridership to crowding on the existing Yonge line, I am not talking about YR contributing to the capital cost of extending it into Richmond Hill (which obviously should be the responsibility of YR) - I am talking about them contributing to building a relief line to ameliorate crowding - which is at least partially caused by ridership from YR. I wonder where the region stands on that.
Isn't densification a good thing by a subway line?
Even if Richmond Hill paid for part of the DRL we would just talking about a DRL that is a diversion (2 stops...Main and Union) it would be relatively cheap. The secondary purpose of a DRL is what costs the money...serving the inner city.
And how much does Torontonians really contribute to building a subway line? How much came from residential taxpayers for the Eglington LRT? This is creating an us vs them when in reality the residents of Toronto don't pay that much towards a subway line.
If Toronto wants to slow down densification in the outer suburbs we have lots of land around subways that are not effectively used. But for NIMBY-ism we have low density (may be a good thing but the cause and effect is high density nodes that need a subway north of Steeles)
Maybe no subway if Toronto expropriates around Rosedale station to build 20 condos and offices?