Then the correct response is to point out that X is hard/impractical/ineffective, supporting your point with evidence or plausible arguments.
Asserting to know better because of your incommunicable personal experience, quite possibly affected by confirmation bias and whatnot, is not a way of arguing, it is a way of refusing to engage in intellectual discussion.
I can imagine people frustrated from having to explain the same concept online for the hundredth time; always to someone else; often to people who genuinely don't know, but sometimes to trolls. That's the moment where people are likely to point to a FAQ. That's why we have the Sequences here. Etc.
The problem is that the FAQ (or the Sequences) usually do contain the full explanation, and sometimes even a place where that specific explanation can be debated. But the sentence "check your privilege" does not. It is not replacing hundreds of explanati...
You know the drill - If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
And, while this is an accidental exception, future open threads should start on Mondays until further notice.