What do you have against Erika, /a/?
It wasn't enough. Her existence felt pointless, even though she was really cute herself. Her character was great, but there were barely any episodes just about her being a cute girl. She's like Hime done wrong.
Hime is basically what you get when you mash Erika and Tsubomi together. For what it's worth, it actually worked, at least during the first half.
Erika is still better