Basically they're saying that they're unhappy with the final part of the story (even though they like the manga as a whole) due to emma's amnesia feeling out of place and unnatural (despite the fact that it suits her overall character arc due to her memories/family being the thing she cares about the most).They think the author added in that plot point because she wasn't sure how to wrap everything up well and wanted to quickly end the story. Apparently this commenter thinks being pretentious and flexing their vocabulary is more important than being comprehensible lol
In deepest candor, allow me to avow that I find myself in a veritable labyrinth of bewilderment regarding the tempestuous umbrage you have elected to embrace; it seems the whimsical jest, offered with the noblest of intentions, has executed a flamboyant vanishing act, eluding your esteemed comprehension with the deftness of a phantom. Let it be known, each carefully curated syllable that graces my lips is sculpted from the very clay of innocent amusement, arising not from any vainglorious aspiration to flaunt the lexical dexterity residing within or to adopt an aura of unwarranted pretension. Ere the curtain falls, I extend a most profound compendium of regrets, lamenting that the delicate tendrils of humor, so artfully unfurled, have, alas, been banished into the abyss, lost upon the shores of your perceptive faculties.
No i get that it's a bit lol (i mean.. your name), i just didn't find it entertaining bc i felt bad for that other commenter. But now that you've doubled down, it is growing on me. Please keep your tendrils, humorous or otherwise, to yourself though bro. I do find this to be a fascinating place to do this joke rather than, idk, twitter or smth, and i respect how fucking long your messages are, carry on, no need to extend even a single regret, let alone a compendium of them

I find myself rather discontented with the denouement, although the narrative as a whole retains its commendable merit. The decision to have Emma experience amnesia ostensibly aligns with her character's trajectory; nevertheless, it strikes me as an expedient and somewhat superficial method to hastily conclude the tale.