My problem with this statement is that you're basically saying that none of the constructive criticism you have received so far means anything, regardless of who it comes from. Because, at the end of the day, you are going to do what you want and write how you want even if it means disappointing your supporters. Now, it would have been fine if you had simply made a point of saying that everyone is entitled to their opinions and that you can't please everyone. To which, I would say that you would be absolutely right. But you didn't say that and it doesn't seem like you ascribe to that particular dogma when it comes to writing.
I just find it odd that you have an issue with so many people criticizing a main character that goes out of his way to help people that do not deserve his help or should be in his life, due to the fact that they are toxic people. Hell, the main character is forced into helping out the woman that manipulated and bullied him in high school, despite the fact that he has no reason to help her. Not to mention, it goes with the weak reasoning that because he "moved on", the MC is willing to help her and her friends out.
When, in reality, anyone would likely make a point of keeping someone so obviously toxic out of their lives. Especially when it's clear that he doesn't benefit from helping them out other than getting poon, which he was just about to get some from someone that actually cares about him. Sure, you can say that he's just being a nice persona and being a nice person and doing good things isn't about a reward. And you'd be right. It isn't. But it also isn't about being a person who is going to let people take advantage of their helpful attitude, as that only opens up the possibility of being used and manipulated like the MC was in h.s.
Pointing that out to people is crucial because it gives a certain weight to the story due to its difference from its inspiration, Masamune-kun no Revenge, where the main character's revenge is founded upon his being cruelly rejected and being given a crappy nickname. In contrast, the male lead of MBIL has a far stronger motivation rooted in physical abuse and emotional rejection by the object of his affections. Thus, making his revenge that much more justified than his predecessor and making for a more compelling story about how easy it is to manipulate someone when they are head over heels in love with you. And, how it can be devastating to a person to experience severe emotional damage due to someone else's malicious or selfish intentions/motivation.