To me it seems like he's using the trademark as a weapon to go after the competition, even through the Wordpress Foundation should be neutral. Many other companies, including his, also make money out of Wordpress.

And I think technically the owner of the trademark is Matt and not the Wordpress Foundation, but also technically, WP Engine isn't required by the license to give him money or contribute back, they are allowed to modify the code and required to share their modifications when they redistribute the software.