I like Laurent, and I take Rakudo more seriously because of him and people like him.
However, in this case his reasoning is specious and his advocacy is suspect, and to my mind it's the same kind of disservice to accuracy that suggests that "just round and then sum and a few pennies here and there aren't bad" is an acceptable level of accuracy in financial applications.
When you start dealing with currency conversions and processing fees and transfer fees and other ways to divide up money and calculate amounts, and you start dealing with tens of thousands or hundreds of thousands or millions of these calculations, a penny here and a penny there represents real information that you're deliberately throwing away.
Double-entry accounting has existed for a long time because it solves real problems. Suggesting that users don't know any better and don't really care, so it's okay for programmers to be sloppy and careless is doing real harm.
