I just checked both my wife's and my profile settings. Both had the correct profile setting. But both of our accounts were our Marriott accounts before the merge. So I'd guess Marriott did have that setting. There may have been a problem with that particular setting coming from SPG accounts. Also,I guess it's possible if one merged accounts and they had conflicting settings that Marriott just dropped the setting. There are probably a few different possibilities.

But I tend to agree that whether a 'form' letter has "Mr", "Mrs", "Ms", etc. is not an issue I'd get worked up over especially since it should be easily fixable. Now if they had a problem pulling my SPG points over, that would be worth worrying and complaining about.