> 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?

No. Education ideally is a gift from society to the individual, in the hope that it will be reciprocated, by work, but also by making informed decisions. And those can easily include refusing to work on a project (military or not) if the individual deems it harmful. Harmful to who? To the society that financed the education, to their family, or to "the world"? That's up to the individual to decide, too.