> Given that society created the environment for these tech companies (and their employees) to acquire their skills and thrive, does not society have some moral/ethical lien on how those skills are applied?

Why do these workers have such a lien, whereas the people who happened to go into a career that isn't useful for the military don't? That sounds quite unfair. I'd say they pay their obligation the same way everybody else does: through taxes. And people who benefited more from that environment will earn more, and subsequently pay more as well.