Silly.

There is so much wasted space in TOronto, even on major transit routes, just look at Scarborough and parts of Etobicoke. Time to densify along the bloor subway in those places instead of adding yet more density downtown. 

In fact it would behoove the city to make development fees depended on existing density. That is, a more dense area than average city density = higher development fees, less dense = lower fees.