HIS ego yes, but perhaps his family was privately embarrased by his actions and knew in their hearts that it would be blasphamy to put him at Arlington. They probably knew it would cause an uproar with the Veteran and miliary familes and didn't want to deal with the backlash.
I realize we're just speculating here, but I find it extremely unlikely that Murtha's family was in any way embarrassed by his actions. Let's keep in mind that Murtha had a long career in bringing the pork home and he was very, very popular at home as a result. He managed to fend off every challenger for his seat (despite my own personal support of Lieutenant Colonel William Russell in the 2008 election); this despite his calling his own constituents rednecks and racists.
And because of that, I find it unlikely that Murtha himself wanted to be buried anyplace other than where he's winding up. For whatever reason, he chose not to be buried in Arlington and while that's perfectly fine by me (Arlington is hallowed ground, fitting only for those who have served honorably and faithfully), apparently he had other plans.
No, sorry, I just don't see Murtha's family doing much more than finalizing the funeral arrangements, collecting the life insurance settlement/proceeds, and investigating closely to see what their options would be in prosecuting the surgeon that allegedly screwed up Murtha's large bowel and caused the infection that killed him.
I can definitely see Murtha's family trying to cash in on everything possible.
Go ahead - call me a cynic.