Disclosure: I've worked at WPE.

Consider that WP Engine's business model revolves around WordPress being a problematic platform for their customers in one way or another. They support sites that would otherwise need to be replaced if it were to continue being scaled. This keeps those customers, the whales, in the WordPress ecosystem.

Plugin and theme developers, digital marketing agencies, and independent web developers continue to put food on the table because of a market that otherwise wouldn't exist. This is healthy for the ecosystem.

Conversely, Matt used that market, the users, as leverage against WP Engine. He caused a deep loss of trust in WordPress as a platform for any serious business. He acted in spite of the community.

I don't think WP Engine is particularly "good", but they don't weaponize users for business goals under the guise of altruism.

Not the only WordPress host and they have no obligation to anything for an open source project.

This story isn't about them it's about their customers who chose to use their service and how Matt chose to make them collateral damage. That choice has consequences which is what this is.

Was WordPress not a fork of someone else's work? Why the double standard?

WP Engine is acting scummy and all, but this is the shadow side of releasing projects as open source. You can't force the people using the freedoms you're granting them to pay you or support you. If you don't like it when people take your code and build a competing business with it, pick a license that (effectively) prevents doing that. With some licenses you can at least get the additions they make out of them under the same license (AGPL and such).

WP Engine is ungrateful and generally kind of shit, but they did nothing that WordPress didn't allow. WordPress acted needlessly aggressive and conflated the business side of their operation with the non-profit side of their operation, which is why WP Engine has a legal basis to sue them over in the first place. WordPress has gathered a lot of good will for being open source and having a non-profit that maintains tooling, but if they don't respect the freedoms that made them popular, they're going to lose out in the end.

I don't have a horse in this race and I'd have to back WordPress if I had to make a decision, but neither party in this conflict is the good guy here.

All of that said, the true vultures here are the lawyers and companies organising the class action lawsuit. All of the customers they "represent" are doing it for a quick buck, and the lawyers are more than willing to blow up Automaticc and WordPress to get their pay day even if it means WordPress will no longer be maintained by anyone. Whatever side you're on, winning this class action lawsuit means everybody but the lawyers lose.

There are several other issues with this, but "1. entered into a formal agreement with the project’s maintainers"

You are aware (well, maybe you're not, because the WPF certainly has never announced it) that this would be ... difficult, because the same day the WPF was granted ownership over the WP "entity", it granted an exclusive, irrevocable, universal sole commercial license to Automattic.