Admittedly, when debating lasers it's not as important, but when debating ideas winning is absolutely essential. These threads are read by the public and don't kid yourself that we're not at war. Winning in that context certainly does matter.
What does it mean to say you've "won" an argument? It sure doesn't mean that you've arrived at the truth. But arriving at the truth is the most important thing. And keeping the discussion unemotional is conducive to a productive argument.
At least as important is your own credibility. If you are seen as disingenuous, supporting arguments that you don't truly believe in simply to feed your own ego, then your credibility vanishes and then later you will not be believed by good people even when you are right.
Bill Clinton lost credibility when he was caught as a liar. His supporters claimed it didn't matter because he only lied about sex. In truth, he lied to the person most important to him, his wife. The correct assumption is that if he would cheat on the person most important to him, then he would also cheat on his country. And it turned our he did.
Regarding lasers, the discussion is important to the pilot who may find himself weighing the relative merit of expensive protective gear. If what Blackdog says about pilot visibility is true, the threat isn't nearly as bad as it seems. And in any case, countermeasures can be easily devised.