The example is strange and contrived. I couldn't torture the logic enough to demonstrate how readability breaks down with exceptions. Reading through the comments, I realise that even if the code is unreadable with exceptions, it can be rewritten to be readable. I updated the article to highlight not only readability, but also compositionality. I also tried to draw parallels with Promises (which are also monadic). I tried to target the article to intermediate programmers that may not already know most of the concerns raised in the comments, and I surely can't cover enough space on error handling without writing a book.

Thank you for the comments. I've learned more from reading the comments.