We can't kill everyone that wants to be an enemy,there is too much replenishment.
Every now and then when an enemy rises in signifigance to the point that he is worth the effort and it will really reduce the threat to go get him, then we ought to go on and get him.
Osama was not born dangerous , I think that the time when he grew in signifigance as an enemy was during Clintons watch, early in the Clinton regime it would have been strange to mount a major operation just to get OBL he just didn't seem all that important , later when he had accomplished more fatal attacks on Americans and others he was getting more attention and more effort in a ramping up of resorces Osama also devoted more and more to avoiding capture or assination, in this era I think the worst mistake was useing important evidence gleaned from listening to OBL cell phone in the conviction of a terrorist at trial, OBL stopped useing cell phones and we lost that handle on his whereabouts.
While president Bush was chaseing OBL overwhelming power was used at times , I don't see how surgeing more or sooner would have garunteed OBLs being caught, already enough was put into Afganistan to win territory at will , would more have been more productive or redundant? I think we learned with the surge that more sooner would indeed have been productive , going small in Afganistan might be the mistake of this era.
While Obama is president OBL actually gets run to ground and shot, can't argue that there was ineffectiveness or bad decisions in the face of success.
Gathering inteligence on OBL started a long time ago and the determination to kill or capture has been long running, what got OBL was persistance.