It failed for SawStop because the inventor chose to attempt to leverage his monopoly instead of licensing the patent. He also charged pretty outrageous prices for the tech -- wasn't it 3k or so a blade? I don't really remember.
And it was, at least in the beginning, self destructive. The original version engaged a breaking mechanism that basically destroyed itself. So a false positive caused by the wood being a little green/damp would cost $300 to get the saw back up and running. I think the new version rapidly drops the blade below the table surface instead of destroying itself.
Still, it fits sixtofour's #1 and #2, they invented a tech, tried to get it mandatory by law, so they could charge large license fees.
Edit: Besides, what IS licensing a patent if not leveraging a monopoly.
When you license a patent, somebody else can take on manufacturing costs and/or risks. Theoretically, there is competition, consumers have options, and the argument for legislation doesn't look quite so self-serving.
