Maybe I am misunderstanding, and I do not want to discuss in bad faith, but the places downtown are wealthier and more powerful. The places that have low density downtown are because of this power. No doubt there has been an effort, but I assume building density in working class and middle class areas are easier than wealthy areas.
I think density should be built in both the core and the suburbs.
I'd like if Toronto could build more sub-cores so that people could commute to places other than just downtown. Easier said than done.