Yep, this is tiresome. Antirez (Redis author) was going to write an alternative to HN, I'm looking forward to that. To this point, I think that a simple Bayesian span detector could help a lot.
I share your point of view, but live coding these days are just beyond that testing programming skills. You must know by heart the most common algorithms out there and design solutions that might involve two or three of them to solve a problem in 30 minutes.
Sometimes you spend the whole time trying to figure out how to solve the puzzle that don't even have time to show that you can - actually - code.
I'm a person just like you, I have dozens of side-projects around. The difference is that I've never went "far" enough to buy domains for any of those.
But I have a decent half-baked AI based investment portfolio manager, one month of hard work (nights/weekends) dreaming of selling it for a bank. Projects of such complexity are impossible for people stuck in the ordinary life (job/family). PS: I'm not complaining - I love my family. But it demands energy.