She's one of the most relatable Persona characters in the franchise. And that just makes her more charming to other people when you spend most of the game surrounded by teenagers with superpowers and are weirdly skilled or attractive for individuals that are apparently supposed to be social outcasts.
>Ann is a model
>Makoto is the model student class prez
>Futaba is a super tech genius hackerman
>Haru is mega rich
>Sumire/Kasumi is a championship level gymnast
>Kawakami is an overworked teacher that's kind of disheveled looking and constantly complains about all the shit she has to deal with, but she's still passionate about trying to be the best teacher she can be

There's also the maid thing, but from what I've seen most Kawakamifags don't like that version of her that much.