Bringer of False Hope
Keima is a false prophet. Plain and simple, he is more anti-christ than anything. Do not get me wrong he is very intelligent. However, unlike the crowd he preaches to, he is well aware of the difference between reality and fantasy. Keima is a very intelligent guy. That is why he managed to succeed at what he was supposed to do. However, he has now set an unrealistic expectation for the masses.
This anime suggests that if you play enough of these dating sims you can go out into the world and some how survive in normal human relationships. There is a reason why all of the girls he rescued had there memories erased. It is because very few dating sims, if any really, go into the relationship portion of a relationship. They all focus on the initial wooing. Which is an important step. However, no matter how good of a house you can build, if you do not maintain the house, it will crumble.
Sadly, most otakus are too wrapped up in the way things should be to really see this. In this sense he is a bringer of false hope. After all, most otakus blindly chase after females who they can never have, or who do not exist. While this anime might inspire a little hope in those poor guys. They will all come crashing back down hard into reality. Like I said Keima is an intelligent guy.
Keima learned how to profile these girls through his games. Most Otakus profile the kind of girl they want to date, and that is it. Keima himself said that he has no interest in Librarian girls. Yet he was more than capable of manipulating Shiori. That is not the kind of thing you can really learn through just playing video games.
Keima is a false prophet. Plain and simple, this is an anime after all. Maybe this is an anime designed to make a few of these Otakus kill themselves. In the end no matter what this anime shows. Females are sentient beings, and will likely rip most of these guys a new one.