It's surprisingly easy to like Promestein since her personality is the one which extends furthest beyond rape and into having actual relatable interests and hobbies.
All you get from a Tamamo is her pretending to be a loli while speaking like a grandma, and pretty much just being a shipper. She doesn't really exhibit any personality traits, just character cliches.
Guess that's why Chrome, Ilias, and Erubetie are all decently popular. Even Black Alice's sheer crazy level and general trolling by attacking other characters' insecurities is quite amusing.
Fittingly, Chrome and Promestein probably got the most in terms of having even more development in Paradox, so I guess even TT knows the fans enjoyed them as being more interesting characters than most of the MGQ cast.