> Why die on a hill that it "is" something it says it isn't?

Because I think they're wrong about that.

If you'd prefer a different metaphor this is windmill I will tilt at.

To provide a little more of a rationale: React code calls the code I write - the JSX and the handlers and suchlike.

It's also pretty uncommon to see React used at the same time as other non-React libraries that handle UI stuff.

Most importantly, the culture and ecosystem of React is one of a framework. You chose React at the start of a project and it then affects everything else you build afterwards.