There is a load of stuff going on with the self deprecating comment stuff and its different for everyone. for a lot of people its just habit which started as false modesty maybe based on a fear of seeming arrogant (which itself might be a fear of rejection)
A while back there was a discussion on my thread and i posted this in a different context.
Its possible that its a passive aggressive ploy to play some kind of victim card. Though in most cases i doubt it is depending on their self image
I suspect that its much more likely that
'I'm sorry I didn't do x, I'm a bad person/husband'
Translates as
'I'm such an awful person and i dont know why everything i do goes wrong and hurts people, i must be really awful and at least that is something we can all agree on'
It may be nothing of the sort, just thought i'd chip in a viewpoint
Both mid 30s, 2 young kids BD 7sep14 XW moved on long ago, now living with OM1 D paperwork in progress