As a user I care enough to make some effort to avoid it such as using old.reddit rather than the new fangled version.

They don’t care about React they care about having next generation web applications with complex state, not some garbage where you click a button and refresh a page everytime to re-render the screen.

No way - users care about speed a lot but usually could care less about a page refresh. That's why React apps are getting a bad rap with users as they are often slow due to poor engineering. If the app is fast and looks good, users like it.

Example - because many developers will fret more about the technology of their site than the actual business. <yes, it's common>