I don't like Ayuni, she's a generic pretty girl.
Try to describe her looks.
Because you can't, since she has no remarkable or distinctive facial features except that she, uh, sweats a lot?
She's just pretty, just bland.
Look at Lingling, she's got her small lips, pointy nose, weird ass teeth and shrill voice.
Atsuko's got an angled defined jaw, charm point on her chin, slightly hook nose, big fish lips, and big eyes.
Aina's got those really angled eyes, tiny nose, toothy smile, and husky voice.
I could do it for a lot of the other BiSH or WACK girls as well. Heck, most of the idols posted here have distinctive features you could describe them by and people would be able to guess who you're talking about.
That is why I don't like Ayuni. She appeals to teens or shitskins, people without distinctive taste. The same kind of people who idealise generic blonde whores, the ones who you cannot really describe with terms other than "blonde" or "pretty", who just blend in with most other women of the same looks. Ayuni is the type of generic pretty girl you'd expect to be one of the generic seat filler background girls in one of the AKB groups or offshoots.