Why do people hate Nickelback so much? What makes them different from other popular bands like Linkin Park, Green Day, etc.? Is it just because they're Canadian or what?

Canadians are generally likeable people , so NickleBack are most likely ok guys.

Even I have cracked a few jokes about the band but I did so not intending any ill will or malice toward the band. Going with the flow at the moment I believe as NickleBack was the topic of the moment.

Those opposed to the band are simply louder and more vocal than the true fans. A matter of opinions.

Glen Powell’s Ex Speaks Out on Actor Leaning Into Sydney Sweeney Romance Rumors to Boost ‘Anyone But You’ Publicity: ‘I Felt Like I Was Fed to the Dogs’ - Variety

NickelBack.

I doubt many hate them for being Canadian. I was going to say no one, but never say never , so to speak.

There will always be that one guy or gal. They may have friends also, so opinions spread, growing in strength , spreading yet further until the humble opinion of one becomes a near fact to many.

Scientists Just Found Something Hilarious About What Actually Happens When Muscle Bros Take Ice Baths - futurism.com

NickleBack may appeal to many, but the majority rules as the saying goes and the overwhelming majority of more vocal proponents voice the opinion the music is bland, generic and commercial, not necessarily in any particular order.

Anyway, why are they so despised in comparison to Green Day, Linkin Park, etc ?? To use an analogy, it is like comparing the smoking/stoner crowd in high school, the athletes and finally the unpopular souls.

BoB's answer to Is Stan from Eminem’s Guilty Conscience the same Stan from Stan?

Red Sox vs Giants Predictions, Parlay, Picks, Odds for Saturday - Action Network