Assuming that comment isn't misrepresenting the issue (I know nothing about Canada and can't say), I think the main focus isn't the unions, but that only organizations that contribute to fattening politicians wallets can build anything. Those organizations just happen to be unions.

A union that is getting contracts because they contribute to the right people is the corrupt devil. A union that provides for their workers salary, safety, retirement, or whatever other good is fine, but many unions cross the line to not allowing non-union workers fair ground to compete with them and that is evil.