What's up with the Mariah and Rihanna bashing?

Mariah Carey has proved time and time again that she's a singer. Her voice may have changed, but I'm sure y'all don't and won't look or sound the same 10 years from now.
YOU WILL AGE TOO!!!
Whitney was great too, a legend!
Let Rihanna do her thang. And it takes marketing to even sell the best singers in the world. So hush now!