Look... Pearson could be the Black River Killer, and that still wouldn't make Matt's actions morally justified.
(For clarity, I'm specifically talking about buying the thesis.com domain name, which he couldn't use because Pearson had the trademark).
It's vindictive and wasteful. Period. That's $100,000 ($132,000 in today's dollars) that could have gone to making the WordPress community better, some other charitable cause, or even a nice vacation for Matt and his family.
I'm sorry, but that is not normal or "principled" behaviour and it's not something that should be "encouraged".
https://wordpress.org/book/2015/11/thesis/
Pearson never made amends; he continued his bad actions long after being called out (and possibly still does).
The correct solution to bad actors is to raze them to the ground; Matt isn't wrong in this. He has the means and is doing something principled with them: Destroying a bad actor.
This should be encouraged; it is how capitalism is supposed to work.