> JSX is just JavaScript

No, it's not. It's the bastard child of XML and JavaScript. I agree that your examples are about the best you can do with JSX. But actually just JavaScript is much easier:

  render() {
    return Bar(someCondition && Foo())
  }

or

  render() {
    return Bar(someCondition ? Foo() : null)
  }

That's not quite hyperscript but it's not far from it.