Unless Eva is lying, the whole Seymour fiasco is pretty dispiriting for the game. They constantly highlighted how they had plans for him, build him up as the games big antagonist, he is also from the design a far different kind of love interest than the other men - experienced, wise, old, but also not a simple lusty geezer like Arthur or Ed. Whenever he ranked low in the character polls, Eva noted their displeasure, since they wanted him to succeed. So considering all the effort put into him and how the entire audience is (rightfully) entirely uninterested or disappointed in him, could have been a huge impact on Evas enthusiasm for the game.
I wonder the opposite of Stan, a character who barely had a role in the game, but the audience demanded him to be more involved and he won first place in a fan contest that just increased the demand. Then he got a do-over and lot's of additional scenes, more than everyone, but in contrast to Seymour, it seems to be that Eva didn't care much about him and wasn't confident in what to do with him, clumsily giving him a voyeur and pity plotline that didn't line up with Lena's usual taste in men and refused to give him good qualities, making Lena fall for him even more inconsistent.