I recommend Bearpaws instead of brand name Uggs. I have one of the higher model Uggs, I forget the name, from a few years ago and they do keep your feet very toasty, the only problem is they’re really only water resistant and not really water proof. Nowadays there are so many good knockoffs (as in, they’re still genuine sheepskin) that your’e better off buying them at half the price. I don’t recommend use with any wet or slushy weather at all.
Bearpaws you can get for $50 on Amazon. Definitely the same quality as Uggs nowadays.
Keep in mind too you’ll want to change the insoles to the bearpaws once a winter. They run about $15. If Bearpaw doesn’t make replacement insoles, Ugg does.
Or, for a less humorous response: they got imported because some people thought they looked cool, and didn’t realize any tackiness. Now there’s been a backlash, as often happens with such strong non-functional fashion statements, but there are still a lot of people for whom the backlash hasn’t hit, or are just unaware.
Finally, there are the hipster types who wear bad fashion and say it’s good. They’ll say they’re wearing them “ironically.”
Uggs are quite fashionable in my area just now. I’ve certainly seen more ridiculous-looking choices over the years – super-pointy-toed shoes and boots, anyone? And I find mine to be quite functional; they’ve kept my feet warm outside on days with a meter of snow on the ground and air so cold it freezes the inside of your nose as you breathe it in.