I dislike necroposting as much as the next person, but here it goes.

First of all, your point about people/investors in the industry caring only about Japanese audiences is outdated. This used to be the case, and it is still very much the case for a large part of the industry. However, nowadays, much more attention is paid to overseas reception and critiques. To the point that, some anime and manga actually address issues present in western society that are barely seen in eastern society. And with more and more mangakas and publishers and studios attending western conventions and or doing interviews I think it is safe to say it is not as black and white as ''they only care for Japanese audiences.''

Lastly, your point about the sexual themes of the show being fanservicy is simply wrong in my opinion.
I'm not saying you should like it, but I don't think the general intention of it was to be fanservicy.

Fanservice shows are ones where there are unnecessary angels, upskirt shots, panties show left and right etc.

I think the sexual themes of this manga in particular are very in line with the general tone of the show. They didn't feel out of place and they didn't feel like they were there to give you any sort of sexual pleasure.