The philosophical concept of freedom of speech and the legal protections of that concept are not the same thing, although the one protects the other from which it derives. The protections are a viewpoint legally enshrined that was common in the political circles at the time and that I still agree with: No matter how much I disagree with your viewpoint, I think you should be allowed to express that viewpoint. If I am a family member or a friend I'm not going to disown or disavow you for them.

I think it is very important that bosses embrace this view too, because otherwise you just get a lot of sycophantic yes-men, an echo chamber. The correct approach is to let everyone be free to voice their opinion before the decision is made: if you don't want their opinions, then what are you paying them for? Once a decision is made it is necessary for everybody to work towards that, but making a good decision requires lots of input, and those who disagreed with the final choice shouldn't be punished in any way, otherwise there quickly won't be any disagreement.