Lack of transaction reversals
How is this a bad thing? Bitcoins are not like credit cards, you don't have to give out sensitive data to make a transaction.
I've heard of a dozen stories about merchants going out of business simply because of chargeback fraud, it is a problem that everyone seems to ignore. Imagine that you sell digital goods such as CD keys and some dude across the globe does a chargeback after he used the CD key, good luck getting your money.