I mean, that simply isn't true. She's an absolutely incredible vocalist, on par with the likes of Mariah Carey, Whitney Houston, and the like. She has one of widest vocal ranges of any current female performing artist and has demonstrated extremely impressive technical ability in many of her recent albums and especially in the Wicked movie. She also has won 2 Grammys.

You may not like her music (which is fine), but it's undeniable that she has top tier vocal ability.