Speaking from experience, it sells better to bring along special soft skills in the package, than yet another technology stack.

Too many coders, generalists or not, cannot engange properly talking to something that isn't a computer.

Those that manage to merge coding skills, with UI/UX, marketing, understanding the customer point of view, already have an upper hand.

Yes, you need soft skills too. But that doesn't mean you shouldn't specialize in something. That doesn't have to be a tech stack either, in fact it's the last thing I would suggest.

That's part of it.

I am also saying that there needs to be a system of incentives, that then, produces, organizational/hiring practices that favor non-tool-specific employment process.

Well, for that your company has to admit it it doesn't have specific problems. Because if you do have specific problems, it's probably more efficient to hire people that can handle those.