I'm pretty sure there are two things the vast majority of music fans can agree on:

1. Music is subjective
2. Nickelback are terrible

Those two items would appear to be antithetical, right? I mean, if music is subjective, than couldn't critically derided bands like Nickelback, Limp Bizkit, or even the dreaded Insane Clown Posse be just as viable as anyone else. Well, sure, but over the years the idea that all of those bands are godawful has been pretty well ingrained into the culture of modern music. Mostly because it's been repeated time and time again. So, am I here to defend those bands? Well, not really. I don't like them either. My inner 10-year-old boy still gets a minor kick out of "Nookie," but that's about it. The point here is simply to explain the role played by music critics; to be convincing enough to give us the impression that opinion is fact. There's an argument for every album being good, that same album being terrible. The job of a critic is to make a convincing enough case for whatever side they take, that we take them at the word.

                        

In this sense, critics - of all kinds - are essentially lawyers. They're presenting a case to the public that a given work of art is either genius, garbage, or somewhere in between. The reason why contrarianism is so popular is because critics love any opportunity to show. If there's a chance to explain why Radiohead are bloated and overrated, someone will take it. Likewise, if there's an opportunity to claim to Nickelback are actually solid tunesmiths, and all you hipsters just don't understand, someone will take that up, too. The key is just to be convincing. There's always going to be discord about the legitimacy of any band or album, and usually, the key to liking something is to make the leap of faith that it's actually good. I know this, because I've often tried to get my parents into the bands I like, with frustrating results  My mom likes plenty of 80's music like New Order, but LCD Soundsystem was lost on her. Because she didn't believe in it. The band that I - and plenty of rock critics - thought was amazing was pretty much lost on her, as she thought she had heard better versions of all this before. We're never going to agree about the quality of any band, no matter how popular they are. That's why there are loads of people who hate The Beatles, and loads more who hate the Stones. Rock critics will be taking on cases for decades, trying to prove beyond a reasonable doubt that whatever they just listened is either brilliant or wretched. No consensus will ever be reached, but there will always be worthwhile arguments.