Actually, the point of a villain in a game is to beat him and thus win the game. Do you know how many games tried to copy BB? A fuckton! Other than Man of the House and School, Love and Cousins Friends, none of them succeeded, because they didn't have a decent story. As much as you may hate it, Eric WAS that story. Defeat him and win the game. Face it, after Eric was kicked out, BB devolved into a copy of one of those copies of BB. The end-goal of defeating Eric was replaced by a dumb "let's make a porn" plot. I'm not saying the villain has to win, but you can't just kick out the villain and continue without one. That turns it into a different story, one that may fail (as the original BB did).
Let's face it, Ds wasn't a really good dev, he didn't understand the kinks,he keep changing how the girls behave, he didn't know how to continue scenes, forgot about plot points that later got resolved in a bad way, he got mad because his game was leaked and changed the plot with the girls, from romance to shit, he kept delaying Lisa's sexual scenes because reasons, he did a really grind game, he kept getting mad that his game was leaked until he decided to drop the game, etc. So knowing that, it's easy to see that he didn't know what to do with his game and made a really bad plot that was the "let's do porn".
But that doesn't mean that Eric was done fine, he was just a walking cockblocker, a way to move the plot with the girls, a really bad one, he doesn't have a great story, let's not make it like he was a blessing in the original game and that he bring a really good story because he doesn't. He is just an easy way to make a challenge, to make the game a bit different from others, but he wasn't that great. He may be the villain but he was there to delay the sex scenes of Max with the girls, nothing more.
There are other ways to make a game "interesting" without needing a villain, in fact he wasn't needed at all in the game. If he was there to make Max feel threatened, there are other ways to make it than making a villain how gets the girls like Ann easily while the hero strugles to see a tit. If he was there to make Max realice he needs to up the game if he wants something with the girls in his family, he also failed at that, since Kira introduced the idea of incest to Max, she helps him and other things, so why is Eric needed? If it's because of the competition, there are other ways to make obstacles with better plot development than Eric so...