I've had to go through a few funerals as well. Death is unevitable for all and I agree with all the horror stories of back biting, politics and most of all family drama.
Most families are like that to begin with normally but I believe in order to desensitize themselves of the fact that a member has just passed away, they continue to do what they always do. (like the death was no big deal) I think they are very insecure with themselves and need this type of commotion in order to avoid the reality that, they too, will one day be in the same boat.
People who do these types of things have a weak sense of faith in ALLAH (SWT) and have no self confidence and most of all have no respect for the marhoom.