It's more about authors trying to excuse that morally wrong part with "oh, this person was just confused, but it was out of love, so it's really OK". Making a character who says "You would end up as a villain, but to me you're sharp, cocky yet studious" is trying to see a good side of a guy who just admitted to grooming his minor student. "Sure, he's a statutory rapist, but he's a complicated person!" Yeah, fuck that rape apologia in the name of "seeing things differently.
I've seen it far too many times in manga , especially with abusive parents. Mother that wrecks her child's life, father beats or molests daughter leading her to suicide attempt? "Oh, they were just mistaken or broken, but they did it out of love, really". Rapist love interest? "He was just from broken rich family, used to taking what he wants, but he's good inside". Mass murderer who horribly kills tens or even millions? Well, he was bullied as a kid, that makes him half-right.
It's not showing different facets of people, if you ignore or trivialize horrible harm your characters cause. What this guy was doing was so immoral he would be fired if found out, and in many countries went to prison, and despite not knowing what love is he clearly knew that. There is zero excuse for him to do what he's doing, only pure selfishness. Everything else is just making excuse for him doing obviously and clearly wrong thing. As inspection of different views on love, it's just shitty writing.
