Selling skin or cosmetic is make easy money for dev and company.
Not only western game many eastern MMORPG also do sell it.
Like people will pay to ride some gorgeous dragon more than use free little pony.
Even the stat equal.

About child prone I can say most of japanese charector design base on child XD.
I can't describe properly but those big eye, round face is child symbol.
Just imagine Saffron get cut down her height and erase her boobs that's the answer.

And about western game is sh*t or not sh*t I can't tell.
Everyone have their own taste and maybe many like it haha.