Kodama is authentic, unlike most authors out there. You know what to expect with her
This is blatantly wrong. As I mentioned above, she has two very different approaches and when you start a story of hers you will never know which way the coin lands.
As for NTR, I'm not sure what all the hate is.
First of all, this is a yuri forum and as hypocritical as it is, most readers here actually quite enjoy when a woman takes another woman from her male lover. It's a whole genre. Well most of my points were already mentioned, but I just wanted to repeat that lol
NTR has dozens of glaring issues outside of "triggering" people. It's pacing is bottom of the barrel, especially in the last third. I have rarely seen a case of "This could have been resolved 10 chapters ago, but we meander for no reason" this bad. If it was stretched any thinner one might think it was secretly a commentary on how the industry forces mangaka to elongate their manga unreasonably... except I cant imagine anyone thought NTR would need to be longer.
The only semi-likeable character was the guy who was cheated on of all people. Which is kind of the point of the NTR genre... I suppose. But this story tried to be "realistic" as you said and instead made everything feel like fetish bait. But unless you are making a pretentious statement about the shittiness of the world at large, common sense is to make at least some of your characters likeable or at least relatable. Neither of which NTR achieves. Hotaru's reasoning for causing this entire conflict is beyond stupid. And not the endearing kind.
Oh and the ending was the most half-assed thing about it. Honestly the hook was the only decent thing about it.
In summary: NTR represents all of Kodama's weakest traits as a writer and deserves the hate. But where other authors would be doomed by that, she has at least some good works to fall back on.