This is not so much about free speech (because if it was, the problem wouldn't exist so much in countries that have a different concept of free speech from the USA), but rather that a scientific education strongly nudges you into becoming a "truth-seeker", and in pursuit of this argue for your point.
This is why in particular geeks/nerds love to argue with their boss when they believe he isn't correct.
So, I rather fault employees that they look for employees with a university degree, while in reality they want employees that don't want to start scientific disputes with their boss ( exactly what the scientific education at a university drills you towards).
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Addendum: In https://news.ycombinator.com/item?id=48918117 silentmafia writes down a related observation:
> In academia arguing is sort of your job, or at least part of it.