I'd be surprised if you've never had a letter-to-the-editor published, so you've probably experienced the reality of a newspaper editorial page. I've had two published in the Murkie, and it cured me of letter-writing. The editing was suspiciously heavy-handed, deleting the reasoned argument in the middle, leaving just an empty assertion hanging out there, making me sound like a nutcase. I have good reason to believe that the editors edit for sensationalism, so it's no great leap to assume that they cherry pick the letters for sensationalism. Unless I can take a look at the letter to the PI that that guy actually wrote, I hesitate to denounce the guy over the letter that was published. They're unlikely to match.

Newspaper editorial pages were once the venue of the great intellectual debates, but those days are long past. Outside of the NYT and the WashPost, where public figures still feel compelled to make their statements in letters, it's degenerated into just grist for the sensationalism mill.

Though the notion that blogs are a superior source of news is absurd, they do free writers from heavy-handed commercially-motivated editing they experience using somebody else's pulpit. The last place I'd look for unadulterated and representative opinion is the letters-to-the-editor pages of almost any newspaper. Give yourself a break and don't fall for the deliberate provocation. You're supposed to be outraged by letters like the one in the PI (and you're supposed to be motivated to write an angry response, to keep the game going); why play their game?