I'm not sure I've ever found myself liking something, reading criticism, and then changing my mind or feeling off about it. If anything, there have been occasions where it's actually strengthened how much I've liked it - not sure I can really explain why though. Maybe on a subconscious level it feels like it's more "for me" if it's less for everyone else.
I do sometimes feel a bit of sadness for the artist if something that really speaks to me isn't going down well more generally, but that's quite natural I think.
I certainly haven't changed my mind about things. But when the majority tell you indirectly that something that you absolutely love, something you listen to that gives you the butterflies and that wonderful euphoria that only music can provide, is terrible, trash, the worst thing the band has ever made, it does make you question things. Are these feelings the music is evoking in me wrong? Are we even listening to the same music? It feels like I'm fighting a battle every single time, and you see so much vitriol for an album that those who appreciate it feel small and insignificant and too scared to speak out because the positive will get utterly crushed by the negative.
Do you have kids? Serious question.
I kind of - not exactly, but sort of - know what you're saying. I have been a Kiss fan since I was 10 years old. I have not wavered (much; the early '90's were a tough time to be a Kiss fan) in all my years, but I know what you mean. Is it too derivative, and I just don't know my music well enough? Is it bad to be so simple? I got into other music - more metal, prog, alternative - but I always seemed to get as much pleasure as anything else when putting on a Kiss record (and forget about live; seeing them at their best - the first reunion tour - was a life-changing experience).
Then I had a kid. And she LOVED music as much as I did, in terms of almost needing it during her day. And she started listening to Miley Cyrus and The Jonas Brothers. And I was, at first, "WTF?". Then she migrated to Taylor Swift and One Direction. And I took her to a couple shows (The Joe Bros. were the biggest at the time), and it struck me: the music itself doesn't matter. There's nothing inherently "better" about Dream Theater or Frank Zappa over Taylor Swift. Sure, there might be a complexity to some of the musical passages, or the lyrical content may be more in depth, but that's really the difference between The Sopranos or Breaking Bad and Seinfeld or Cheers. Is "The Sopranos" better than "Seinfeld" because there is sex and violence? Nope. And so to me, Taylor Swift is no better or worse - objectively - than Zappa because it's simpler, or it talks about - GASP! - feelings. I watch my kid get as giddy for One Direction as I did for Maiden and Kiss, and I'm just happy she found something to immerse herself in. And, truth be told, we've shared our music. She's now a Kiss, Queen, Def Leppard and Fleetwood Mac fan (I feel Elton John is next, though maybe Van Halen) and I think Swift's "Wildest Dreams" is one of the greatest pop songs ever written, "Once In A Lifetime" by One Direction makes me cry every time I hear it, and I went and saw Harry Styles at MSG on his last tour (and he KILLED it). His solo album is WAY underrated, too. If you're a Bowie fan I can see you liking it.