Isn it impossible to voice a dissenting opinion without appearing rude or impolite?
No. Lawyers do it all the time. So do politicians. So do many people on this site. It can take practice, but everything can be worded politely and respectfully no matter how strongly you disagree with someone. For example, I don’t believe that the Earth is flat, but if I were discussing this topic with someone who does believe that the Earth is flat, I could respond in two ways: “You are a complete moron! Everyone knows that the Earth is round!” This may be a true statement, but it is neither polite or respectful. “I see what you’re saying, and I agree that the Earth does appear flat when you’re standing on the surface, but that’s because it is so large. I’ve also seen pictures of Earth from space, and it’s definitely round in those pictures.” This is polite and respectful because it acknowledges their point of view, e.g., it is respectful, and states my point-of-view in a polite and respectful way.
