I see them being referred to as "great", and "classic band", but usually I don't see them traded in the "Greatest band of all time" list. Case in point, just randomly pulled one list up, this list puts them at #29 of greatest artists of all time. That's by no means bad, but it's also nowhere near the top.
Ok, great we're getting somewhere. As a critic, music or film, it is not their job to rate a film/band based on how much they LIKE it. They are supposed to give a score based on how good it is. Since there's so many variables to film and music, it's very hard to pin point everything and you just can't completely master the craft of giving something a rating. But as you can see, a band like The Who pretty much fluctuates between #5-30 or so. Seeing as how many bands are out there, that's amazing. Now, when you get to comparing the top 50 or so bands of all time, this is when it gets very complicated, but comparing The Who to Miley Cyrus is a joke. Why is there such a thing as "professional critic"? Why do they need to go to school for it? Why not just go to the theater and tell their boss if they liked it or not? If everything is "just an opinion", then what do they need to learn?
The very fact that we're even discussing this for 10 pages speaks volumes about what I'm trying to say. This would only go to 10 pages on something like Dream Theater forums. Go to a Justin Beiber forum and try talking about this...they will be confused about what music theory even is, and that's ok. They don't listen to Beiber for musical talent, they listen to him for their own reasons. That is completely fine. But compare Dream Theater and Justin Beiber, and there is no comparison as to which is the more talented artist. Ok, it may be unfair because Bieber is only one person. Yeah, he can sing really well, but can't play guitar very well, can't play drums very well, so DT already has the edge. There's a reason why Rebecca Black is so hated...she doesn't know what the hell she is doing. She is incompetent at the craft of making music. Sure, you can like her music, anyone can LIKE anything. I can bang on my table, call it a song and like it. But the talent difference is night and day. And talent=something you're good at. If you're talented at something, you're good at it.