"Chaotic” and “bombastic” are YOUR adjectives, that's not a true description of classic Etta as far as I'm concerned. Would you rather modern Etta have punny relatives, an obsession with candy and say "Woo Woo!" a lot, would that somehow make her more acceptable to you? She serves much of the same function regardless, she's Diana's first girlfriend in Man's World and assists in her adventures. Rucka had Steve make with the wisecracks and Dr. Adrianna Anderson for comic relief, so it wasn't necessary for Etta to do that for Rebirth.
Attachment 117053
Attachment 117054
See? Same function, rallying the troops and giving orders.