+1. All you have to do is take the text of the email and replace "woman/female" with "fat" or "Black" to understand the offensiveness of the joke. If it had been all about the individual, then fine; but the joke referenced Worgull's sex four times.
One of the major motorcycle racing sites did a similar joke in a non-sexist fashion this year. The gist of it was that a long-time also-ran racer in the US national series was going to replace one of the four top riders in the world championship. It was clearly a joke at the expense of the US racer (who has enough of a sense of humor and a good enough relationship with the writers at the site that it was okay). But there was nothing in the "story" about it being a breakthrough for rednecks, aging riders, or any other general group to which the US rider belongs.
Honestly, a simple apology would've been plenty as far as I was concerned. It wasn't that big of a deal in my mind. But five paragraphs of excuses along the lines of "some of my best friends are women" doesn't do anything to endear Trek to me.