Apocalypse mcs in mangas

I’m reading a book called “I am a Hero” which is a zombie apocalypse psychological horror type of book and it really made me realize how scummy protagonists like him are. It’s a common theme “I’m a sad lowlife with a shitty job so I spend my days looking at p^rn magazines and fantasize about being dead” why is that such a common theme? Why are they all perverted?? On a vv rare occasion it’s funny but other times it just turns me off😪. The mc of “I am a hero” was a manga artists who despised his boss and from what I can tell is a schizophrenic who often seems creepy and hideous shit, he surprisingly has a gf but because of his insecurities he accuses her of cheating on him because she somewhat preferred her exes manga work than his. It would’ve been better to talk to her about how he felt instead of asking “Has another man been inside you”. I can’t say much about the mc yet until I fully finish the series (I’m on book 5-6 I read hella fast) but from what I’ve seen he’s just a weirdo- mans literally tried to pay a dead taxi driver for the fare before running off, he has a sprinkle of morals but that shouldn’t kick in during a life or death situation. Couldn’t be me. I’m breaking every law.