separation != joining the US
There is small but loud group of chronic whiners who hate everything (often including each other) pushing the former.
Almost nobody is pushing the latter.
A separated Alberta would become a de facto Puerto Rico in thrall to the US without any votes.
That might be the rhetoric, but separation means joining the US. The experience of landlocked country would be one of getting taken advantage of by every country around it.
There is a good 20% of people in Alberta who would vote for separation today. Take a close look, they aren't voting to be an independent country surrounded by a hostile country around it and a superpower that hijacks oil tankers to the south.
https://www.cbc.ca/news/canada/edmonton/red-deer-alberta-ind...
It is a stupid idea because the level of changes that would have to happen to everything would be much, much more than people realize. But Brexit has shown us that people will vote for stupid things if they are sold by trusted-but-dishonest actors