If you just look at the timeline and even that response to DHH it feels to me that he has much resentment against others using the software and him not being able to be the largest beneficiary of it. The examples to Shopify being a billion dollar whatever and unable to capture, to applying for the recent trademarks around "Wordpress Managed" and such show me that's how he views it in the end. You are using "Wordpress" software, so he should of course get a cut of that.
So many companies in the ecosystem have "WP" or "Wordpress Managed/Wordpress Hosting" as their tagline and have been for over the past decade. WPEngine is just the biggest target and the first in line. I have no soft spot for PE, but both can be bad in this case. I feel like Automattic is willing to burn the community to the ground or fracture it as long as they get their cut or become the the biggest player.
"Capturing value" I suppose.