I suspect they're taking issue with the implication that these things are universally life changing, not that they can be meaningful at all. I have no doubt the author of this article uncovered personal truths, but the whole thing is framed as if they become an expert on everyone else's mental health by breaking free from their own depression.

Personally for navel-gazy articles like this I think it's more useful to focus on telling one's own story instead of making broad edicts and sprinkling in some science in an effort to lend legitimacy to them. What works for one person won't work for everyone, but "I was in X situation and did Y and it helped me" is far more likely to be helpful for someone else than simply "Do Y", especially when you're writing for a wide audience.