Man, I am glad I don't have to work with any developers for whom having to write "className" (which has been in the DOM standard since 2000) over "class" is a deal-breaker.
To be fair though, that's not a JSX restriction, that's a React choice. (In my own JSX-based library, I allow `class="thing"` and `for="some-id"` just fine as simple synonyms of className and htmlFor.)
