"That’s only economical if your time is worth nothing." Well, we should all be able to live lives where we can pursue things that do not have monetary rewards. Obviously not everyone is in that position but perhaps for David Florian exploring and learning and trying things is what makes him happy. Of course for him it probably makes money as well, even if indirectly. The fact that his video got shared means more people will see it, and more views means more money, so there's the value for David Florian. It's also worth considering that in science, it's all about trying things and gathering information that will hopefully lead to new (and hopefully lower cost) capabilities.