It's not a perfect system, but still today in Montréal you can get a $400USD 1 bedroom apartment in a good part of town, thanks to this system. It ensures that the working class can live near their occupation, and they don't have to commute from a slum neighbourhood outside the city. In many quartiers, you have the very poor and the very wealthy living side by side.
I believe absolutely rent-control (in tandem with a few other policies) has enabled Montréal to situate itself as a hotbed of creativity. We have one of the most dynamic and diverse art scenes in all of North America, and with a population on the island of Montréal still less than 2 million.
I definitely support this kind of legislation.