To those leaving negative reviews, it's important to note that this novel carries genres such as "Action, Adventure, Comedy, Ecchi, Fantasy, Harem, Mature Romance, and Shounen." If you dislike these specific elements, likening a poor rating to disliking a Western film due to the absence of cowboys might be an apt comparison. What was your expectation when choosing a novel with those tags?
In terms of its classification, this particular "Mature Ecchi Harem Romance Comedy with Shounen Action Fantasy Adventures" offers a satisfactory experience. The main character often relies on unconventional thinking, but the narrative provides a reasonable explanation for his actions. He has earned his place and seeks enjoyment, occasionally eliminating obstacles that interfere. Along the way, he even offers guidance to the new hero.
Regarding the spoiler, my understanding is that the protagonist was sent back home initially because rival factions intended to exploit him. He didn't resist as he believed he could return, and by then, he had compiled a list of desires from Earth.