Yes he is absolutely dead. The government actually has video of his dead body along with DNA evidence taken by seal team 6 at the site of his death. The video wasn't released to the public because of it's brutality (Osama blew himself up rather them be caught) but they have it, trust me, having military sources can have it's advantages :)
For all we know it could be a cover up I'm not saying it is but for all we know they probly have Bin Laden locked up somewhere for secretive interrogation or questioning if he had anything planned secretly or working on secret nuclear weapons etc. there's no telling what's real or not it could be a cover up or he may actually be dead we may never know.
yes, why do people still hang on to this...i get it, he killed a lot of people ut you need to accept that he died. when people make claims that he still lives they are opening old wounds for those who were hurt by him