As with so many things in life, just because it's extremely popular doesn't mean it's really any good. Don't ever use popularity as a basis to say something is good, ever.
I could go on to say that more than 50% of Americans are absolute dunces, but that would make me sound like the jerk that I am and might upset some people who are sure they are not dunces, even though 50% of them are.
For what it's worth, I can get past the whole popularity thing and say that I actually enjoy some of Celine Dion's and Shania Twain's music from time to time. And the fact that they are above-average looking women doesn't hurt too much. But for the most part, I try not to be too shallow. I also listen to TONS of music performed by VERY UGLY MEN, if that proves anything.