Not sure why you're objecting, here. No one said "directly," and "primarily" specifically leaves room for the fact that they could sail into the wind. Maybe yo

Not sure why you're objecting, here. No one said "directly," and "primarily" specifically leaves room for the fact that they could sail into the wind. Maybe you missed the context: the comment responded to the claim that it's a "misconception" that "sails work by the wind blowing on them from behind."