To answer your first point: there are plenty of games here that don't have an antagonist and are way, way, way, better than BB, so please don't talk like BB is the greatest game of all, just because you like it, because it has many flaws. Great game with good story, yeah a mother that let his new boyfriend control everything that happens in her house after literally one date with him and just do it because she is submissive, or a brother that think the best way of gaining money is doing livestream of their family members by hidden cams, yeah those are some of those great points, surely it gets an award 10/10 IGN, would play it again. Let's be real the story is bland, a guy wants to fuck his family but there is another guy that is stopping him and he must get rid of him if he wants to get some. Dude that's not really a great story. Great characters, that fall in types: we got the slut (aunt), the sub (mom), the shy (lisa), the bitch elder sister (alice), the asshole villain clitche (Eric) and the creep (Max) amost others. BB might have been a great game at the start, because there weren't many great games during those times, but right now it's fine but not the greatest. Most players think it's great just because of nostalgia, nothing more.
Now about Eric, not being needed, well the character that moves Max in the way to wanting to fuck his family isn't Eric, is Kira, she is the ones the makes Max target the family, she is the one showing things to him, while Eric is just there to be beaten, nothing more. But if you think he is great and really needed fopr the game good for you.
The second point: Hating a character doesn't have anything to do with real life. I hate Eric because it's a clitche villain, which role is to halt the progress Max could do with the girls before you kick him, he is a bad writen character, with plots that are all over the place and who just have everything in the game withot really trying, and he was even worse in the original. You couldn't do shit to him in the original, he always won, until you kick him, so those times made me hate him as a character. I can relate to a well writen villain and even like some, but sadly Eric isn't one of the well writen.
The third point: I'm not saying that if he doesn't remove Eric I won't support him, read again what I wrote. I said that until he is gone I won't think of even supporting him, because I hate the Eric character, right now the sex content of the game only involves Eric, so why would I want to invest in something that I don't like? Again read better before jumping to conclusions.
To the four point, many people don't like him, many won't support a dev that does content they don't like logically, so if Eric is there it limits your content. A good game doesn't need an antagonist, that is the easy way to make a game different, "interesting" to some, the hard way is making a good story, one that doesn't need antagonist or heroes for it to catch you, and we have a few of them in this site, games with a good story, with and without some kind of antagonist.
Next time don't jump to conclusions and read before talking, because dear god the bunch of stupid things you wrote were over 9000.
