So timely. In another HN thread, I simply raised a point that drunk driving wasn't the largest threat to road safety based on statistics, and was labeled an apologist drunk driver.

The real problem is that if you put your ideas out there, and someone says something like that, and you don't respond, they've gotten the last word, and your silence is a patent acceptance of their point (as it would be in a face-to-face debate). So we try to guard our opinions with "This is just my opinion" (duh, whose else opinion would it be?), or try to beat others to the counterpoints, and when you are constantly setting up defenses to your ideas, your idea loses a lot of potency and clarity.