I thought the whole HN mantra (and one echoed in this article) was that ideas are worth less than the paper they're written on, and that execution is everything

I thought the whole HN mantra (and one echoed in this article) was that ideas are worth less than the paper they're written on, and that execution is everything? It's still a dick move to blatantly rip-off a peer like that, but still. He took a good idea and did well with it.