I find that the ability to trivially make the equivalent of Rails "helper" functions as auxiliary methods on the Component class actually tends to encourage sep

I find that the ability to trivially make the equivalent of Rails "helper" functions as auxiliary methods on the Component class actually tends to encourage separation of logic - it's the same file so there's no context switch needed. On top of that, since JSX makes ternary statements look much more elegant than bracketed if statements (whose conditions can be a great hiding place for complex logic) it further encourages breaking your logic out into auxiliary functions.