I have little sympathy for those who decide they need to impose unjustified rule, taxation, force and protection private property against the workers. There's a third side to the chasm, if such a thing could exist.
Is it unjustified? By what measure? Alcohol taxes fund the social welfare system, and alcohol taxes the social welfare system. Alcohol tax is rationally connected to it's purpose. It isn't arbitrary, and if it does infringe on your rights (very dubious argument), that infringement is minimal. Alcohol tax doesn't outright prevent you from purchasing alcohol.
As you surely know, it isn't merely taxes that are at work in most provinces. Retail monopolies are another way to keep prices elevated, but even more, they expressly forbid competition in sales and distribution, which cuts off potential markets. There's no question that this infringes on the ability of people to exchange freely.
As to the effects of alcohol (or cigarettes, etc) on the social welfare system, this may be another argument against the social welfare system, or at least the manner in which it tends to operate. If the result is that government must creep further and further into regulating/taxing the lives of the population in order to control ever-rising costs, then something is quite awry.