Requests containing elements of hostility, shame, or injury frequently serve dual purposes: (1) the ostensible aim of eliciting an action and (2) the underlying objective of inflicting some from of harm (here shame) as a means compelling compliance through emotional leverage. Even if the respondent doesn't honor the request, the secondary purpose still occurs.
But it isn't a given that this will be successful; the outcome of the resulting conversation may well be that shopping malls are, or a particular shopping mall is, more desirable than wetlands, in which case the ostensible respondent will be less likely to comply than they would have been without the conversation. And, in this case, it seems that the conversation is strongly tending toward favoring the use of things like Grammarly rather than opposing it.
So I don't oppose starting such conversations. I think it's better to discuss ethical questions like this openly, even though sometimes people suffer shame as a result.
To me the request in question seems to be in the same spirit as "Please don't play your music so loud at night", "Please don't look at my sister", or "Please don't throw your trash out your car window". In each of these cases, there's clearly a conflict between different people's desires, probably accompanied with underlying disagreements about relevant duties; perhaps one person believes the other has a duty to avert their gaze from the sister in question to show respect to her chastity, while their interlocutor does not subscribe to any such duty, believing he is entitled to look at whomever he pleases. Or perhaps one person believes the other has a duty to carry their trash to a trash can, while the other does not.
Given that such a conflict has arisen, how can we resolve it? We could merely refrain from trying to influence one another's behavior entirely, which is the lowest-effort approach, but this clearly leads to deeply suboptimal outcomes in many cases; perhaps the cost of turning down the stereo or carrying the garbage to a trash can would be almost trivial, so doing it to accommodate others' preferences results in a net improvement in welfare. Alternatively, we could try to exclude people whose normative beliefs differ from our own from the spaces that most affect us, but it should be obvious that this also often causes harms far out of proportion from the good that results, such as ethnic cleansing.
All the other approaches to resolving the conflict that I can think of—bargaining, mediation, arbitration, collective deliberation, etc.—begin unavoidably with stating the unfulfilled desire. Or, as you put it, hectoring someone to 'stop doing this'.
Undoubtedly, if you devote the minute and a half required to read my "wall of text" comment above, you will be persuaded by its reasoning.
My concern is that the flagblasting and moderator-scolding, while certainly justified by the comment in question, will cause the collateral damage of discouraging politer versions of such comments in the future. So I think it's worthwhile to affirm that criticizing people's behavior to their face is not in fact inherently dickish, but rather a much better alternative to doing it behind their back, or to finding ways to silently exclude them, or people you suspect of being like them.