(C94) [abgrund (Saikawa Yusa)] Summer Halation After Episode

Asking here because why not: Why are Japanese men perceived as weak and spineless? In almost every NTR doujinshi, they never fight back and in some cases encourage their women to be violated by other men. I read somewhere that women in Japan are becoming more assertive and in a traditionally conservative society, men don't know how to handle it and thus aren't as compatible with their women anymore. I don't know ANYONE in real life that would ever let this happen. Cheating? Sure, but the shit that goes on in these comics? Never.