I wouldn't judge that book by it's cover. The Atelier series does pretty well for itself judging from the LPs that I have seen of it. I would recommend reading the first part of one of those if you want a real picture of what the game is.
Especially since this more about an admittedly weird Japanese cultural thing than anything.
People always seem weirdly eager to defend the sexualization of children and childlike figures when it's anime.
Hey guys, I just found *insert pedo-baiting anime here*, its kinda trashy what with *flaw that is not the sexualized preteens* but I really like it for *thing it is also not the pedophilia*. Oh whoops, wrong thread
Seriously tho, I think its the exoticism? People are used to the idea that they don't understand "eastern" cultures, and its true there's a lot about anime that is closely connected to Japanese culture. But on the other hand a lot of the fanservice is a pretty simple, universal "sex sells", which has to get more and more niche as the genre expands. And sexualized children seems to be a rather
large niche among anime audiences.
Or, you know, they watch it because they're into that. Or they watch anime that sticks to more standard targets for fanservice and have learned to look the other way when an otherwise normal anime has an awkward moment.
But yeah, anyway. Even people who are ok with the kind of anime we're discussing would likely not be as fine with, for example, the Powerpuff Girls reboot drawing the girls in the style of Strike Witches. Because then there wouldn't be the "its another culture" excuse.
And yes, I did just make this entire post without using the word "loli" because then I'd have to wash my mouth out with soap and I don't like the taste of soap.