this is not a bad day for founders; it's Matt having gotten to the end point of his value as a leader
Don't get me wrong: getting to a point where you have 2,000 employees and a 7 billion dollar valuation is a massive accomplishment. He was clearly very effective at various parts of the company's history. But it scaled beyond the point where his skillset and personality could continue to credibly steer the ship
As someone who's personally been bitten by this particular WP Engine misfeature, describing this as a "fork" is disingenuous at best. The average Linux distro ships way more out-of-tree changes than WP Engine ever did.