Also important to mention is the fact that polio is a lot more dangerous(as well as various other vaccine-preventable diseases, and I suspect that Joe Jihad isn't carefully checking the labels on the vaccines before shooting up a medical team). Even if there had been no other way of getting to Bin Laden, so what? An aging man, allegedly in tepid health, is one of those problems that solves itself sooner or later. Endemic polio, on the other hand, is one of those problems that tends to get drastically worse and more difficult unless solved as fast and hard as possible.
The CIA's willingness to, in effect, use public health workers as human shields is abhorrent and unethical(yes, it's very quaint, I know; but the Geneva Convention considers attacking medical personnel, even if they are exclusively to provide medical support to your enemies, a crime, this isn't exactly a new or controversial concept); but it's also stupid. Bin Laden is barely distinguishable from noise compared to the threat posed by infectious disease; and even if you only care about American interests specifically, you have to be pretty naive to ignore the fact that all it'll take is a few carriers booking a downmarket Hajj travel package and it'll be all over the place, and from there a few hours by air to anywhere in the world.
It's really a total shitshow on every level: putting medical staff in the line of fire (even the ones on their own project were allegedly dupes rather than volunteers, and totally unrelated workers have suffered the blowback as well) is ethically shoddy even by the CIA's notoriously high standards.
The willingness to use such a tactic is also inexcusably myopic and/or arrogant: even if there were no other way, knowing when the gains couldn't possibly the worth the costs is an important skill, and one where failure to do so has a definite chance of direct damage to our interests, never mind those of the locals.
As for the near-silence on the matter, I'm shocked that the media would be largely craven and supine in the face of a story that requires weighing risks, something people don't do well, poking uncomfortable holes in triumphal tales of victory, and saying potentially hurtful things about Our Protectors...