The loss I refer to with respect to students who stop using their second language after being in immersion in high school also applies to people who end up in a job where they cannot use their second language, or in an environment where that culture does not exist. Ultimately, the culture of the organization depends on the leadership of the person in charge of the department, who will impose that culture.
I fully agree with you. And that culture is a lot more intangible than simply saying to people they will take 40 hours of courses in French as a second language for six months. It requires other strategies and very definitely a political will to bring about change.