Programming a chess engine is how I want to spend my precious time right now. I don't see why this can't be the next "long term goal" that you spoke of which provides a focus point and energy and all that good stuff the site in your link spoke of?
That's on completely different time budgets. Some of my time is to be spent in solitude, giving my mind something interesting to chew on, allowing me to recharge my social batteries. Having a family doesn't mean you have to sacrfice all your individual interests - the goal is more like harmonious cohabitation.
I disagree for the reason stated above. But in addition it's also a good exercise for any programmer. Tree search is part of every university curriculum for a reason. In chess programming you explore that concept much deeper and hone your intuition regarding problems with exponential time complexity.
Those making contributions to Stockfish have learned the necessary skills by starting at the beginning at some point. As a beginner it's very motivating to see other programmers actively developing engines of similar strength. I also don't think those that run tournaments and maintain lists and rankings would find that much fun if no new engines would enter the competition anymore just because they can't compete with stockfish.
It's probably hard to find someone from this community that is less knowledgable about chess programming than me at this point. That doesn't disqualify from trying to teach and pass on the knowledge you have gained so far. Only if you can explain something well you have truly understood the material, teaching is the ultimate test of your knowledge.
Even though my last video has had less then 100 views I've received a handful of very appreciative comments. One comment said "I've started on my own chess engine as a novice programmer, and you explain things very clearly where the chess programming wiki can be a bit dense at some points, or worse missing information." I'm not meaning to brag. The point is that peer-learning has specific advantages over traditional setups like student/teacher or just learning on your own from books.
Define "something" and "useful" please!