I once considered it. It was more profitable to flip the upzoned site to a Cidex type. They probably will make more on property management. In my experience, their equity partners got most of the pie when they sold the first set of rental towers to Hydro Quebec or some public entity in Quebec.
They aren't selling condos to people. They are selling towers to corporations and entities. It's not a whole lot different. They will keep building as long as they can keep selling. The buyers are also to blame for the cheapness.
Their success is definitely dependant on people buying (or renting) the units they build. The problem with that is most people are completely clueless about how to look for quality and have no understanding about anything other than the appearance and layout of the units they buy. The same problem exists in the SFH market, lots of really shady developers throw things together with shoddy labour and cheap materials, but disguise it well with nice looking finishes. Not sure there is a solution to that though, people will buy what looks nice and shady developers will always focus on the finishes and not mention the bad foundations or leaky roofs.
The funds hiring full service design, build, and, manage companies like Cidex to develop rental real estate assets are as clueless as renters and they have a lot more input on the direction being taken. Al they care about is Cidex delivering on their promises as far as asset value and income. It either doesn't compute that Cidex is providing the bare minimum and they could do better with potentially longer term stability by putting more emphasis in design and livability or they are not truly invested for the long term. My take is that it's another real estate bubble.