The word "Hoser" does, in fact, derive from SCTV's Bob & Doug McKenzie, Strange Brew being the movie based on those characters. People who were around in the early 80's when Bob and Doug were briefly quite popular (around the time the movie was made) recognize and understand the word "Hoser", but I wouldn't say they actually use it. It's tossed around as a semi-obscure pop culture reference from time to time.
My buddies and I would casually refer to each other as "Hoser" in high school... it became a fairly commonly recognized thing, around the school, anyways. And for me in particular, it stuck. I was also the first guy in town to have a "Canada Kicks Ass" t-shirt, before they became popular...
Actually (rambling badly now), I had a graphics class for which I had to make a "company logo" as an assignment for my "graphics company", so I drew up my Hoser Graphics (TM) logo. This was then extended and slapped on anything I did (my film projects were always by "Hoser Films", etc.) Anyways, one assignment was industrial design and a drew a car, which was made by the fictional company "Hoser Motors" (of course). I dubbed this car the "Hellspawn", because I liked the alliteration, and thought cars should have COOL names. (What the hell is "Camry"? "Corolla"? "Impreza"? What happened to the Mustangs and Vipers?) THEN, I made a video of myself getting into this fictional car (primitive special effects and compositing) and driving away in the Hoser Hellspawn. The video took months to make and was my major project for that class. When it came time to select online handles for things, "Hoser" (Canadian, humour) and "Hellspawn" (irreligious, evil/cool-sounding) had all the elements I figured I'd want to project.
And that's why the sky is blue, Jimmy.