Users have responsability for what they do. We do not take responsability for them. We give them enough information to make their informed decision.
In my opinion, that's the ethical way to do things. In my opinion, we ought to take responsibility for the recommendations and assistance we give to others. Thus, we should not steer people towards non-free software. Even though they are not forced to follow our advice, we are still responsible for having given it. In BSD land, we trust the human nature. We're not condescending to our users, we treat them as adults and we let them make *their* own ethical choice and take their own decision. You cannot claim the credit for "letting" them, because it is a fact that they can do so in any case. It is misleading to speak of "letting" or "stopping" the users from installing non-free software. What's really going on is that you are helping them use the non-free software, which grants it legitimacy. That is what I object to.