Canada is much different than Singapore, which is a condensed country with a highly centralized government. But urban planning and authority in countries like Canada and the U.S. is delegated at a local level, and sometimes from there it's even subdivided by neighborhood. And to understand the decisions of the local leaders, you have to understand the incentives for the people who vote them in.
Suppose you own a house or apartment in a highly desirable neighborhood with very low housing supply. When you want to rent it out or sell it, there are a hundred people lined up to pay. To maximize your payout, you should charge the highest possible amount that the richest person of that hundred will pay. That's a lot of money! Let's call it $1 million.
But suppose your neighbor is also selling. Well assuming all else is equal, if you charge $1 million, he can just charge $999K and the richest guy will move there instead. So the ceiling is now whatever the second-richest is paying, because that's the point where it no longer makes sense to underbid your neighbor. Let's say your property value is now $975,000.
Okay... now suppose the government comes and says, good news, we're going to build public housing on your street that will have hundreds of homes! The hundreds of buyers will be ecstatic of course, but every new home dilutes your selling power. And you know who's going to be REALLY angry? The guy who just paid $1 million to live here.
This is the basic incentivize structure driving "NIMBYism," short for "Not in My BackYard." That term is derisive because your average NIBMY claims that they don't oppose development or public housing per se, but boy, they just keep finding reasons why their neighborhood is not the place for it. The building will block their sun! The "wrong people" will move in! It'll strain the budget for our schools!
The politicians at that level do not work for people who WANT to move to their districts and cities. They work for the people who DO live there. And the NIMBYs are far more motivated (and usually more well-off) than the people for whom not living in the neighborhood is a purely theoretical loss. They become single-issue voters and donors, warping the incentive structure for those politicians to block development.