This explains why so many lawyers involved in our family’s estate affairs are so dumbfounded with us - We don’t piss in each others’ Wheaties over estates (sadly, this has been demonstrated three times in recent years). I thought it was just the laywers blowing smoke up our collective skirts, and trying to ego-stroke us. Nope. It turns out that a large family that doesn’t squable over estates is something of an odditity. 
Death and estates make people weird sometimes. Often its just straight greed, and that’s unfortunate but at least it’s honest, I guess.
For some, the dividing of the estate symbolizes the absolute finality of death and they have difficulty dealing with it, so they drag it out as long as possible, even if doing so hurts the other relatives and is ruinous to the estate.
I had a distant aunt who refused to accept her mother’s will and dragged it out for almost 10 years over an endless series of one petty thing after another. She and her siblings were looking at a sizable inheritance and eventually ended up with almost nothing. The only reason it ever ended is because she herself died. No one showed up at her funeral or the reading of her will (she didn’t have anything left anyways).
One of Charles Dickens’ novels is called Bleak House, and while I have not read it, I understand that the plot is driven by the legal case of Jarndyce and Jarndyce, a dispute over an inheritance. In the novel, the case stretches literally over generations, and in the end the estate is consumed by legal fees. So this sort of thing has been going on for a while.
Also a chance to get payback for old hurts or resentments, including/especially at the deceased, with whom there will now never be an accounting or reconcilliation.