I think the creator created those puzzles not to distribute his bitcoins to everyone. I think the motivation is to know how safe bitcoin is, or how powerful the new hardware now. The puzzle creator don't care about the average joe, he cares about the bitcoin security.
To do this, you don’t need to create a puzzle, the creator is not an idiot, he knows perfectly well what equipment there is in the world and how much time it will take to puzzle resolve. The issue of security research is not in front of the puzzle maker, he is just laughing and mocking us, wasting our time is this not clear? Do you watch shows on television? So this is the same thing.