Trudeau's flip flop is an example of what I'm talking about, so i don't understand your use of the word "but" in the first sentence. Once in power, a party is interested in maintaining that power. Since the current system got them into power, they are unlikely to be interested in reforming it (other than with a system that would solidify it more).

I don't live in BC anymore, so hadn't realized that there had been another vote in 2018. That is disappointing.