Also Paula Abdul was a singer, Ellen was a comedian, actress, and talk show host. But not a well known singer.
Why not give the gig to Alan Thicke or Arsenio Hall?
Some of the criticism on the show is needlessly cutting and cruel; she tended to empathise with the performers and her comments usually took the sting out of the harsher or more inane criticism. I think she added more to the show than she was given credit for, mainly for humanizing it.