I'm not saying they shouldn't contribute; I'm saying there's no universe in where you should be forced to give 8% (or any amount of) of your revenue to another business as a tithe to be allowed to use GPL software.
It's the method of extraction I'm disagreeing with here, not that they shouldn't contribute to what their business runs on.
And yes, technically it's the Trademark we're discussing rather than the software, but, ultimately, not being able to use the name of the thing is the same impact from a business perspective. Especially because Matt made sure that only Matt has a license to use the name and Matt is the only one who can decide if Matt should allow someone else to use it, also.
It'd be like Linus saying that Canonical can't use the Linux trademark, and then going on an unhinged rant in public about how it's theft that they're using his trademark.
community that is supposed to lift us all up
Sadly, Matt is busy lighting that community on fire because he thinks he's owed something for a business (which he also used to own a major portion of, for the extra lols) using GPLed software, which is also something I, in general, disagree with: the whole point of free software is that it's free. If you want to get rich, make some proprietary software that everyone must use.
creating and sharing WordPress
The hilarious thing here is that WordPress is, itself, a fork of GPLed software. Not saying he didn't spend an enormous amount of time and resources on improving it, but B2 is the reason it's under GPL (since Matt would probably have picked a different license, if he could have.)