Thanks for bringing attention to this initiative...and let me start by saying you are right...there's often nothing more permanent than a temporary solution. And yes, other more long term solutions must also be implemented. But this is one way to deliver affordable housing, by utilizing 'free' land. I would add that the modular housing demonstration projects could deliver about 190 of the 550 'short term' units proposed by the Mayor.
Your readers interested in addressing homelessness might also want to check out vancouver.24hrs.ca/solutions where the short list of ideas generated by a recent contest can be found. They can even vote! Cheers