The theory was that the pay would be made up by the much higher than nominal pay from door close to door open. $30/hr for a relatively unskilled job with the benefits that go with it is nothing to sneeze at. That number goes up to $50/hr after 5 years of service. Delta, which doesn't have union flight attendants, was the first to pay for boarding and deplaning, that rate is half the hourly pay of when the door is closed. Other US airlines are doing similar things as their union contracts come up for renewal.
If AC gives the FAs what they want, it's going to be the end of AC. It's going to more than double labor costs. Labor costs in the US airline industry went up 20% and a whole lot of people are complaining about ticket prices. AC would have almost no ability to compete internationally, while Porter and Westjet would continue to eat away at their domestic share. Since they can't actually do anything, it's going to be on the government to decide if AC will continue to exist. They have to force binding arbitration with the union.