Hmm - I think you mean to say that when interoperability is not a core constraint, then there won't be an incentive for an open standard.

That's important because in plenty of other software - databases, OSes, compilers and binary formats, networks, etc. name your favorite CS topic, there is an open standard for it.

You can either achieve interoperability by... achieving interoperability, or by dominating market share and edging the user's action space to solely stay in your ecosystem (change the action distribution of your user) that for all intents and purposes that it "interoperates with everything" means that, "since I bought entirely into this ecosystem, I interoperate with everything".

So ultimately I agree with you, but to present it as a failure of objective engineering prowess on open source is weird. As you said yourself, it's clearly the network effects that prop the business model. And sure, gaining market share isn't a trivial task, but it's not engineering.

I think framing it in the interoperability way is healthier - because it actually provides a potential new out to work towards, rather than this weird beration double-bind that frames Microsoft's approach as The Objective Way to do things. It's not and doesn't have to be.