He may be the most hated man in America History but I think the moral thing to do would have been to capture him and bring him to trial, but that apparently didn't enter into consideration.
I'm not sure I agree that it's strategically valuable - in an asymmetrical engagement, it seems like this just provokes sympathy and stokes recruitment.
Treating him (both of them, in fact) with dignity, respect, and an honest public trial including an accounting of their crimes might help, though.
http://www.theguardian.com/world/2001/nov/01/afghanistan.ter...
And then there's the possibility that Osama was long dead before the raid (which former Pakistan PM Benazir Bhutto stated a month before she was killed).
With less airlift, and presumably an emphasis on extracting documents and computers, there may not have been capacity to bring captives.