Yes, the Canadian courts understand precisely how the internet works... through Canadian ISPs who can be forced block traffic from some companies and not others.
The point of the ruling could be summarized this way: "If you wish to do business in Canada, with a web business that's visible in Canada, then there are certain practices you can't be guilty of elsewhere or in general."
This isn't new. For example, it is commonplace for governments to forbid domestic contracts with businesses who, elsewhere in the world, employ bribery in their ordinary course of business. Same general concept here. Don't be too surprised if tactics like this emerge elsewhere to combat online gambling, for example, since gamblers and online gambling companies have been adept at getting around superficial blocks.
It's also commonplace to allow lawsuits in the U.S. that seek to penalize governments and other institutions for conduct that happened outside the U.S., but affected people in the U.S.
A previous parallel issue in Canada concerns the publication of Federal Election results; I don't know how energetic Canada has been in enforcing it lately, but the idea was to not allow Canadian media or ISPs to facilitate publishing any election results outside a given Province until the whole country had voted, since voters in the West might not even go to the polls if they knew that the election had already been decided by votes in the East. (Canada spans a lot of time zones.)
Given the difficulty of limiting information exchange over the internet there aren't many alternatives to rulings that take into consideration a company's conduct elsewhere before allowing them to freely communicate in one's own country.
Whether you like the specific reason (trigger) for this principle being invoked is an entirely different question I don't address here; but yes the principle is logically coherent and enforceable.
It's also interesting to think about the controversial Fight Online Sex Trafficking Act in the U.S. in this regard.