"Musician" is a bit generous here.

It's one thing to not enjoy her music, to which you're entitled, but she's definitely a musician and an accomplished one whose talent is widely recognized by others. So, not generous. Accurate.

She doesn't play an instrument, write most of her songs, is heavily modified in recordings and lip synchs in a lot of her concerts.

Also at best, she is a singer but a singer is not quite a musician according to some definitions (but not others).

This the first I've heard that her vocal ability was called into question. Sure, we can say that of lots of popular artists, but it's surprising to hear that about this one.

Also, I've never heard it disputed that vocalists are musicians and I've studied vocal performance my entire life. In fact, musicianship and musicality are both taught as key concepts one must have to succeed as a vocal performer.

She's not the worst singer but all these manufactured pop stars have help now. Very, very overrated. None of her songs are memorable to me apart from the "Single Ladies" one.