It seems like you're suggesting that if the "lifestyle"-type techniques described in the article aren't a solution to your specific situation, then it's condescending and useless to describe those techniques. I don't agree, and I don't think the author was proposing to lay out some universal program for eliminating all forms of depression. She was merely describing what was helpful for her.
Obviously people who have more serious conditions may need different interventions, and needless to say there is a whole pharmacopeia of chemical tweaks to be explored above and beyond lifestyle modifications. Those are also valid and valuable.
The blog post is not properly describing the person merely was having a rut. Temporary unhappiness. Not clinical depression. However saying all that up front would make the post far less interesting and make the person far less interesting.
Clinical depression isn’t that serious or a condition for some people. It still isn’t the non factor the blogger had.
First thing first: did the author had clinically diagnosed depression? Or was a self-assessment?
What would people think if bloggers start giving advice on how to sort out cancer because they felt some lump in their leg, self-diagnose and decided to cure it with massage? Or giving advice on how to cure cirrhosis because their liver hurt for a couple of weeks. But with depression, for most, it's fine.
Obviously people who have more serious conditions may need different interventions, and needless to say there is a whole pharmacopeia of chemical tweaks to be explored above and beyond lifestyle modifications. Those are also valid and valuable.