Buta Koushaku ni Tensei Shitakara, Kondo wa Kimi ni Suki to Iitai - Vol. 2 Ch. 11

[Boomshakaking]

The premise of the anime without the reincarnator has too many plot holes. If Slow loved her, why did her treat her badly? If Charlotte started to love Shuya just because he saved her once, what about all the times that Slow protected her? He protected her from the shadows, but it was also shown that he did it in front of her too. If it was because Slow was unattractive, why would Slow go out of his way to make him look unattractive? Becoming fat isn't a necessary point for him to be disowned by his family. I also don't see why the people that watched the anime would like Charlotte. She discarded Slow for a random dude(from her perspective) that saved her once. When compared to how people IRL behave towards that kind of development, that would only give reasons for them to dislike her, some would even hate.

If there's one thing I appreciate about this manga it's that it doesn't overexplain much so it gives the readers opportunities to connect the dots on their own.
...but, that's as far as the story of this continuity goes, not about the "original" anime's storyline. I completely agree with what you said about the plot holes about the reactions to the original anime's story, especially the part about audience reactions. Taking Slow's recollection of the story at face value, no matter how goated Shuya could've been as the MC, I don't think anyone would've taken kindly to him basically ntr-ing Slow by having Charlotte join his harem. The only way I could ever see Slow's reputation being a mixed bag for the audience is if his behavior was just actually THAT egregious towards Shuya/Charlotte/the other students in the anime that even when his backstory was shown and was revealed to be a decent guy all along and a savior to Charlotte, he's still made out to be a bad guy. (Though I guess if I think about it like this, I can see the illiterate and the "characters can't change their image from their first impression" crowd being haters...but it's still stupid to think about.)
Honestly if things had never changed and Slow still kept up the a-hole pig act, I can see Charlotte switching over to Shuya as her just being tired and being over Slow. I can vividly imagine the writers of the anime justifying Charlotte joining Shuya by saying that even if Slow was protecting her in the shadows, he wasn't fulfilling her needs currently so it was only "natural" for her to fall for Shuya. Probably not enough of a reasoning to stop "Charlotte is for the STREETS" memes from popping up tho LOL