When I was in Portugal I didn't see a lot of people DOING drugs, just a lot of people SELLING drugs.

It doesn't. Did you read the link?

Legalizing isn't supposed to keep people from getting addicted. It ends up being able to provide people with more treatment once they are addicted or have been addicted.

A reduced chance of dying in a way that doesn't physically harm other people.

In America, it makes sense to me because the prison systems are so ****ed. I have very little knowledge of Canadian prisons though, because if they had an effective rehabilitation system, that might shift my opinion on it a little bit.

I can't seem to find info on that anywhere. All I managed to come across was this site here which basically just puts Canada in as a middle of the road drug using population. Lower percentages than US/UK/Australia but more than Germany/Sweden/etc.

I'd assume that living in Canada would be enough to turn anyone into an addict, but I guess they can't grow anything up there.

BC weed is some of the best **** in the world dude.

How?! Isn't it a tropical(ish) plant?

Idunno. Probably hydroponics, basement growing, greenhouses, or well done outdoor placement.

But, aside from potential differences in local growing culture, shouldn't hydroponic weed not be affected by regional differences?

You just answered your own question. It makes a big difference.