There's no doubt that they can all sing, but I just find them all boring. I think it's that they are all trying to be "current" and most of the female songs at the moment are nondescript and boring.
Rihanna seems to be the most famous female singer in the world, but I could only name or hum/whistle one of her songs. (Umberella, ella ella) The songs are just forgettable, but the girls all want to be successful like her

But that's how the general public likes them! No votes for Miss Sassy or Miss Personality.

That is what the public are told they like!