I can't stand Celine Dion's music, but I never listened to any of her records, just the stuff I heard on radio and television. Somehow, yes, I tend to think this kind of music (and lots of others) is the enemy of taste. But before I ever assert or expand this cheap point, I'd need to listen to her records, like I did lately for Shania Twain.
I can safely say that I don't like Shania Twain's music at all, though her first album isn't too bad (just harmless, like some early records of Allison Moorer - imo).
About the matter of taste, I have reflected about it on my own, and I'm convinced it's something you learn. Taste belongs to culture, education, knowledge, experience, and life. It's something that evolves all the time as early as you remain curious and never cease to discover new musics, or new artists. Nothing definitive about taste.
So: is it wrong to like Celine Dion's music? Yes and no.
No: the way one loves her music can be beautiful and interesting. It's a subjective matter that's not directly related to "taste".
Yes: let's not neglect the damage that "bad culture" does to the masses, for hiding the good one, and keeping from evolving.
Of course I could bring more tinges to my points, but frankly, my english doesn't allow me to be less "schématique".