Conversely, I see zero value in this kind of reactionarily pessimistic you're-average-at-everything-and-even-if-you're-good-you'll-probably-fail-anyway stuff that always turns up on any encouraging article.

You get zero points for being able to say "See, I was right" when someone fails. Completely aside from that, it's factually wrong; people on this site are quite likely to have skills and resources that the average person cannot comprehend. Being a "decent programmer" is a fabulously valuable skill in the modern world. You aren't guaranteed to be able to leverage it into capital right away, but if you work hard and get out of your own head it's fully achievable.