Contracts -- and law in general -- describe in detail what kinds of actions will allow another to bring legal force into play against you or vice-versa.
But there's all kinds of actions that I can legally take that don't conform to norms that will invite condemnation and reprisal through means other than the legal sphere.
Not every obligation should be given legal force; not every action that's strictly legal will turn out to be socially okay or consequence free.
In turn, that can affect how likely others are to view those companies favorably and/or cooperate with them.
e.g. I favor Prusa 3d printers over other vendors because Prusa provides substantial resources to development of the tooling that we all use. Other vendors are (usually) compliant with the contract, but may not be seen as good citizens by everyone in the community, and this can have consequences even if it doesn't have legal force.
I understand that some people didn't always understand the consequences of their choices, or maybe wrongly thought we all agreed on these unwritten social contracts, but we don't agree at all and I hope the lesson is learned well.
P.S.: This all having been said, while I think that there aren't commonly-shared unwritten rules w.r.t. who may do what with open source software pertaining to its copyright license(s), I don't think there's absolutely no "unwritten rules" in open source. For example, I think the CLA rug-pull pattern is a pretty dirty trick, but that has little to do with open source licenses and more to do with outright deceiving people. And even then, it does beg the question of why you would agree to sign something that explicitly grants that right when there is absolutely no reason to do so.
Even that wasn’t free enough for some. Permissive licensing allows you redistribute software without even disclosing your patches.
These are radically different to regular contracts.
But there's plenty of things people can do with freedom that bring consequences; they just don't bring legal consequences.
They are that less open source software will be created and made available to everyone with permissive licensing. More software will be produced either commercially, or with more restrictive licensing. Less software will be produced overall, because of the overhead costs of enforcing these restrictions. The culture will shift from a norm of "Here, use this thing I made if you want!" towards "You'd better not be using this thing I made without paying me."
This formalisation of norms into explicit contracts backed by legal enforcement would not necessarily be a bad thing overall, and it may be a necessary thing in a "society" where there are too many people for everyone to know everyone else personally and establish trust that way. But it will be different. There will be winners and losers.
If Automattic wants to force companies to pay for Wordpress, it should use a license that encourages/requires that.
There are additional and unwritten obligations in everything, that's just what a culture is. And open source culture has always relied on a general goodwill extended to strangers, it is what keeps it alive. If we only abide by the letter of the law and take as much as we can and give as little as possible open source is just dead, I mean you already see this with large open source contributors moving towards more restrictive licenses.
Saying that the conclusion of this is that licenses were too generous and that we ought to be suspicious of people because they take the underling ethos seriously is... strange to say the least.
There are no consumer protection laws for businesses. There is no cooling off period for certain contracts. Businesses are supposed to have the legal wherewithal to protect their own interests.
You can't project our social norms to businesses.
Companies aren’t people, they are social constructions which can, or not, have positive or negative impact on the society but ultimately live for making money. And I don’t mean this as an insult, it’s just that if you want to work with other people with other goals than making money, a company is just the wrong structure. I think it’s crucial to stop that belief that companies have souls. Companies souls are what is wrote in their status, nothing more, nothing less.
Generally speaking, these constructs are created to solve problems an individual may have trouble with.
The constructs have no agency. They must act through people and are directed by people, but are not people.
Perhaps we should treat corporations like people and jail them, like we do people.
What would that look like?
Freeze all assets for a period of time? Or, since they are essentially shields for those directing them, maybe remove the shield part for X period of time...
This only makes sense in the point of view that every obligation should be enforced by courts. However public opinion can sway people to fulfill non-legal obligations or else have their reputation tarnished. WP Engine reputation is pretty damaged due to their behavior of being a "taker" rather than a "maker".
Informal agreements like this work between people who know each other, not for agreements between strangers. The terms in an open source license are intended to be universally applicable, to make the obligations clear for anyone who reads them. This includes total strangers and companies that didn’t exist when you published the code.
Those strangers shouldn’t be expected to abide by anything not explicitly written down in the license. If the license doesn’t document the obligations you expect of anyone, you used the wrong license.
We should be suspicious of people who try to claim that there are additional unwritten obligations for reusing source code. Open source licenses have very generous terms, maybe too generous. They allow takers. That’s how it works, you can take it.