Maybe someone can explain what the issue is because I don't see it.

That they would forbid their holy language server implementation from integrating with other editors exposes the perfidy at the heart of their advocacy.

If they want to keep the extension proprietary and charge for the language server, that’s fine! But allow people to use it with whichever editor instead of forbidding it through the license.

It’s wholly malicious to use a language server implementation to extend control to the editor landscape. This is exactly the kind of nonsense that got them in trouble in the 90s, in the first place.