I don't like using phrases such as (objectively) "the best" or "the greatest" to refer to any song/album/artist since music tastes are subjective, but I can easily say this: Yes is one of the greatest
musical acts ever. Musical tastes cannot deny genius.
They can't be that underrated if they've got a huge fanbase.
Compared to what? Garage band acts? If you're looking at major rock acts, even on Spotify, 1.5MM isn't that huge. Garbage (not garage) bands like KISS have 4.2MM, and even similar acts like Genesis have 2.3MM (although a sad majority might be engaged in their post-1983 work). Not to mention Progressive Rock is still a bit of a stigma in itself. Yes are most likely the most well known Prog band, so it comes as no surprise they get most of the hate associated with the genre. Many people dismiss Prog without ever hearing a single song from the genre because they've been led to believe that it's all pretentious bullshit (even one of my friends was like that two years ago, but luckily he became enlightened soon after). While I won't deny that boundary is crossed often enough, it's still a gross oversimplification either way.
I am envious of anyone who is listening to Yes for the first time. I would pay a stupidly large amount to be able to go back 3 years and hear them for the first time.
Edited 2/19/2018 04:29:37