To be fair, writing if statements in JSX is messier than it should be, but this is the fault of JavaScript and not JSX. If statements don't return anything, so we have to either create an immediately executed anonymous function (like you showed) or use a ternary operator. I'm pretty sure the author knows that you can put if statements in JSX but is frustrated that it requires boilerplate, which I think is a valid criticism. That being said, I greatly prefer using plain JavaScript over custom DSLs like Mustache.