We do it through facts and data. The linked comment is obviously misadric, but all the rebuttals are mostly sarcastic and will only put people on the defensive.

I am mostly a lurker, but I have a great deal of respect for /r/MensRights because they show so much decorum. I figure posting something like this every once and a while can reminds us that when we see a post like this, we take a breath and avoid unhelpful posts. Truth is our most powerful weapon but it cannot be used like a bludgeon.

edit: Here is the link: http://www.reddit.com/r/AdviceAnimals/comments/17nlyx/feels_good/c875ht2