Lastly for everyone that wished harsher punishment for the tutor I just think there's a dissonance in value. What looks to us like grooming probably doesn't look like that to a Japanese audience. So let it go I guess 🤷
Considering that he did basically mindbroke her for I think few years until she met male MC, which easily could result in her turning into plaything of increasingly abusive boyfriends, like in some Emergence/Metamorphosis type of hentai, while being her tutor, I don't see why we should let it go when it's one of most important part of the plot how her current situation was harmful to her in result of her relationship with her years older tutor , which is then ignored by manga as "life experiences".
And just because some Japanese are fine with it, doesn't mean all of them are anyway, or that we should ignore it if some of them do. There were probably plenty of Japanese that were fine with Usagi Drop's ending, that doesn't mean people can't criticize the choice of making girl adopted when 6 year old crave adoptive father's kids as soon as she turns "legal".
As for TVTropes and Amazon reviews mentioned in other posts, firstly TVTrope is is not review page, it lists tropes used by author without commenting if given story does them well or badly. So it's absolutely useless as an argument about quality of the story, or about whether Meguro did develop as character or regressed. It just records author's intentions. And as for Amazon reviews, you'd first have to show me that their manga ratings can be critical in general. People who bought 11 volumes of any series with their own money are usually very biased towards liking the manga, so it's not surprising it can get 4.5/5. Even here most manga have ratings between like 8.2 and 8.9, with Meguro's current 7.08 - which looks like positive rating - being very low rating for this site and fitting the streams of criticism.
Best example is Rent-a-Girlfriend which is still pretty popular despite its bad writing, though with slowly dropping sales, so "some people who bought every volume of it still like it" is not really good argument. Everywhere I've seen where people aren't invested with their money, vast majority was as critical of the ending as people here.
EDIT: And one other thing I noticed with Amazon, while ratings didn't drop, numbers of reviews did, and by a lot more than usual. Stated at 842, ended on 120. That's 7 times less reviewers. I browsed few other series, and I didn't found any with such drastic drop. To compare, "How to Grill Our Love" was below average with getting from 1886 to 636 at volume 11 and 324 at volume 17. And the drop was mainly within first 4 volumes of Meguro-san, and slowed later, so like 2/3 of Amazon readers of first volume just stopped buying the manga after 3 or 4 volumes.
Also I didn't see a single series were ratings dropped by more than half of star, and even that was very rare, mostly it was either 4.5 for every volume or 5 also for every volume . When you display manga as "full series" it's easy to see and compare both numbers and ratings, so I consider rating argument as pointless. People on Amazon just don't drop the ratings, they stop buying next volume.