The main issue at play is that Matt used the blog of a GPLv2 project to attack a competitor of his own for-profit venture for playing by the rules — disabling revision posts is an official and documented WP feature. The point is: if Satan themselves decides to use and make a profit off based on WordPress, he is allowed as long as they follow GPLv2, which is the case with WP Engine. (Satan as an alternative example for a PE equity is not by coincidence, btw.)
This is unacceptable behavior for a FOSS project leader, not to mention his explicit conflict of interest by running a for-profit company rival to the one he tossed under the bus exploiting his power and position in the community.
If you can't see what's wrong here, I'm sorry, I can't make this clearer.