@AkodoRyu
Welp just wanna say for starter that you’re probably right about most readers, including me, not having experienced a long, ~10 years, relationship, but even considering your points, I do think he deserves the hate he’s getting.
As you said, You MUST have liked Michi or their relationship would’ve failed ages ago, but the main issue is his personality as a whole. You, from what we seen, is the type to go for what’s the most convenient. Ever since high school, he developed this personality, and from his past relationships, it’s confirmed that he’s pretty insensitive as well. I’m just assuming but there’s a very likely chance that all his past relationship weren’t ended by him but instead, by his partners. Like someone stated earlier, he’ll most likely think breaking up is too bothersome. Sure, Michi was somehow fine with this, but that doesn’t take away from the fact that You’s indifferent personality is really irritating. Even if Michi’s fine with this, it’s not wrong of the readers to point out his huge flaws, and it’s not like Michi wouldn’t want You to be a better husband.
Also to your other point, yes, Michi barely demanded anything from You but when she did, like during her promotion exam last year, You did nothing. Sure, you can make the argument that Michi didn’t actually ask You for help, but she was clearly over stressed and told You about the exam. They may have developed a status quo in a long relationship, but when You’s so insensitive that he didn’t even notice Michi’s struggles and just shrugged off her outburst, he deserves the hate. And the fact he didn’t even realize how much Michi’s changed in these past few months just further shows his unlikable personality. You doesn’t have to help around the house or be overly affectionate, but the very least he could do is pay attention to Michi. It doesn’t take a rocket surgeon or brain scientist to figure out why they were having so many arguments lately.
As for You’s lack of intimacy, I don’t think ED can explain his lack of intimacy starting 2 years ago. He became over stressed because Michi was “demanding” it from him. In these 2 years, Michi completely carried this relationship, and even if 2 years doesn’t account to much, You still burdened Michi for 2 WHOLE YEARS. I can’t speak from personal experience, but for my partner to suddenly stop showing intimacy after a long relationship for even just 1 year would be so painful. Unless there’s a actual reason for the lack of intimacy, the subtle message it carries is huge. In Niina’s case, he even doubted whether Kaede loved him or not. Sex may just be activity for You, but for Michi, it’s probably one of the only times You’s shows his full affection. The fact is he never considered Michi’s wants until Michi finally spoken up. He may not have purposely avoided Michi, but it doesn’t take much to just fulfill your wife’s needs and show her some love (talking bout during 2 year span).