It's an important question. I think part of it is also about asking who these projects are profitable for. They're certainly not for the local communities, as we've seen from the reports by the Auditor General.
I live in Ottawa. For those people who don't live in Ottawa, you might not know that for quite some time the P3 for the light rail transit here was basically a bad punchline for pretty much everyone in Ottawa, because of the lack of accountability and democratic oversight and the cost overruns, and because of the fact that it took well over a year past deadline to move forward at stage 2. That's just one example of a very problematic P3 in a slightly larger community.
It really comes down to how these projects aren't in the interests of people or communities, but serve to increase corporate profits.