The impotency pills only last for that evening, so he's free to nail Ann in the morning, or later on in the week. And having sex with Ann by pretending to be Eric to me is a "meh" victory. I want Ann to know it's her son as he takes her. That's part of the fun of incest in my mind. She has to know it is her son, and be torn about it, or guilty a little bit, before her inhibitions fall away.
The problem is that to many of us, the race is already lost once Eric starts screwing your family. After that, it's just trying to make the best of a bad situation. In other incest games, the bad guy screwing your sister would end the game. Instead, you're expected to keep going. I get that that is fun to some people. But people with that kink don't seem to get that others hate that.
But he wasn't inserted properly. At least not in the context of an incest game, which many of us thought this was supposed to be. That can't be changed, barring a major rewrite. But I suspect people would still hate Eric.
Max shouldn't be so weak though, just as Eric shouldn't be so strong. It's Eric's existence that's partially to blame for Max being so weak. In turn, it makes the player themselves feel weak, because they feel helpless against Eric and what he is doing. That's a turn-on to some, but again, it's agony to others. It would be more enjoyable to me if Max wasn't such a wuss, and if he were allowed to develop as a character. The game starts with Max becoming more capable via the online lessons and so on, but none of that really helps him against Eric, because it seems like you're just supposed to repeatedly fail against him.
Why should we have to work with anyone at all though, let alone someone who is trying to have sex with the entire family? Working with Kira, Olivia, or Kate are one thing. Those are better thought out. Maybe it's old-fashioned thinking on my part, but I don't really see them as competition. There can be challenges added to the game that don't involve the MC being forced to accept being cucked to one degree or another. But for some reason when people say the game is too easy, they go immediately to "so we need Eric back", which is a huge leap.
It's an incest game. As has been mentioned, the goal should be to have sex with certain people who are related to you. Sharing them could be part of that, but it should be optional, or at least more easily avoidable. Not partially avoidable, where he only screws some of them, or only gets blowjobs, or stuff like that. All the game needed was a way to get Eric out of there early, like maybe when he starts going after your sisters. Instead, when you try to use that or any other situation against him, it ends up blowing up in your face.
What pisses a lot of people off so much about Eric is that until he shows up, it's shaping up into a very nice incest game. Then it goes NTR, and seems designed to keep it that way. Without fan outcry, I think Eric would still be dominating the game, because I suspect that was the plan all along. To the extent that the backlash has reduced the difficulty of the game after Eric is gone is regretable. But bringing Eric back is not a solution. At least not if the problem is how to make an enjoyable incest game.