Good ol' Matt, never happy with anyone else making a dime off of WP.
You could say the same thing of Jonas Salk who patented the polio vaccine precisely to protect the vaccine and keep unscrupulous people from taking advantage. If you have something that you want to remain free and protect the integrity of the system, you have to have a license of some sort. If it gets released into the public domain, you lose control.
But Salk did not prevent people from making money off the polio vaccine, as long as they did so within the terms of the licensing agreement. Similar here. Matt is perfectly happy with people making money off Wordpress, as long as they observe the conditions of the license.
And actually, Matt never had any real choice in this. Wordpress is a fork of b2/cafelog, which was licensed under the GPL as of May 2002. [cafelog.com...]