Unfortunately, that didn't sell all to well when HOTD was coming out. Even though it was on the tail end of the "Ecchi Era", it wasn't until animes like Fate/Stay Night, Steins; Gate, Madoka Magika and Psycho-Pass came out that people started deviating away from ecchis and towards action with deeper meanings.

HOTD has psychological musings and social collapse buried under more fanservice and impossible boob physics than Ron Jeremy's house