This may come of as facetious but I must unironically argue that Takeuchi's talents as an artist come through very strongly when drawing explicit content.
He's someone whose style's strong point lies in the dynamic of his posing, with the interplay and relative positioning of elements being what gives it strength. In this sense, despite his other weaknesses, Takeuchi is a fairly impressive artist. I bet he'd make an incredible storyboarder for anime.
But to tie in with my first statement, this quality which he excels at is exactly what any good sex scene requires. The
and
joining
relative positioning
of
.