The author does not say the advice is stupid. She says that it is stupid for people suffering from depression, which she acknowledges is not likely the target

The author does not say the advice is stupid. She says that it is stupid for people suffering from depression, which she acknowledges is not likely the target audience of the original piece. (In fact, the target audience was Aurelius himself, since his Meditations were more of a personal journal than a work intended for public consumption.) This article is not in any way criticizing the writing of Marcus Aurelius; it is simply using it to point out an unhelpful mindset when dealing with depression.