One really common case is when person A says something to the effect of, "I don't see why B people don't do X instead of complaining about fooism" — but X is an action that is (relatively easily) available to person A, but is systematically unavailable to B people. (And sometimes because of fooism.)
Or, X has been tried repeatedly in the history of B people, and has failed; but A doesn't know that history.
Or, X is just ridiculously expensive (in money/time/energy) and B people are poor/busy/tired, or otherwise ill-placed to implement it.
Or, X is an attempt to solve the wrong problem, but A doesn't have the practical experience to distinguish the actual problem from the situation at hand — A may be pattern-matching a situation into the wrong category.
Some of this post could totally be rephrased as being about "non-depressed-person privilege", but the author doesn't write like that.
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.
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.