I think there's a general feeling on this board that Marriott's integration issues are huge and affect millions of people (the SPG data breach did affect millions, but it's unrelated to the IT integration). However, for many people, including many here, the integration has gone just fine and we've experienced no problems.
So we're left with two sides: One which feels that the mistakes Marriott has made, and the resulting issues individuals have experienced, are so great that they are un-recoverable, and the CEO should be fired. And another that feels issues should be fixed, but that they only impact a small yet vocal group of customers. The second group can read an end of the year, happy holidays email for exactly what it is, and not have to analyze every word that was or wasn't included.
It's certainly rational to believe that Marriott should do something to make it up to affected customers. But it's not rational to think that a standard, planned, annual customer email (which this year acknowledged the integration issues) should be the cure.