He's always been pretty open about his "just get the job done" approach. That's exactly what PHP is too. Not beautiful, well designed etc., but gets the job done in most cases.
That email is confusing. "From: damien taylor" in 2003 yet signed "Walter Bagdasarian", which unusual-seeming name belongs to a guy who was convicted in 2009 of threatening Obama. Odd.
Making threats has been a "something" that's considered a crime for... well, a long time. Typically the law requires that the threat be at least somewhat believable in order to be successfully prosecuted, but there are certain types of threats which are criminal regardless of ability to be carried out (e.g., threatening to plant a bomb in a public square is a crime, even if you have no way of building or planting the bomb).
This is a mail he showed at a talk - http://lerdorf.com/fanmail.txt
I'm sure he enjoys it when people get worked up about PHP :)