I can't really get behind incumbent manufacturers failing to pay the inventor of a technology a significant portion of its value, which is, at minimum, the cost of hundreds of severely injured or completely severed fingers.
It isn't just that they wouldn't pay the license, it's also that they didn't develop the safety tech themselves in the first place. They presumably applied the Fight Club formula, to determine that the company's liability when people slice fingers off with one of their saws was not enough to justify the cost of actually doing anything about it (beyond writing into the operator's manual "let's don't cut any fingers off, mmmkay?").
If one of the incumbents had invented it, the others would have licensed or counter-patented incremental improvements and cross-licensed, recognizing it as a competitive threat.
But since an outsider patented it, that's a minor threat. What can a little guy do against a 100-year tool brand? And if he has to enforce, that means they're not playing by the rules, which are to pay the inventor's license, or wait until the patent expires.
Why are severed fingers part of anyone's business model?