I'm not sure I understand why some would question the burial at sea. What were we supposed to do with his body? Give it back to his family? 
Just as you have "birthers", you also have "deathers", people who won't believe that he's dead unless they can see the body themselves. (Expect Donald Trump to jump on that bandwagon as soon as he can get over
this creaming he recently got.) I was a little dissatisfied with the burial at sea too, until I remembered Graceland. If people would line up for hours to see the resting place of the king of rock-n-roll, imagine what al-Qaeda junkies would do with the resting place of this mass murderer...and besides, if I heard it right, we offered his remains to Saudi Arabia and they told us to take a hike. No one wanted his body, most likely for the reason I just gave, and so the only other solution was burial at sea. Apparently, while there is an Islamic tradition for burial at sea, there isn't one for cremation -- which is what I would have done if given the chance.
Or, no, actually, if given the chance, I would have greatly preferred to have them haul his ass to lower Manhattan for trial. But, well.