The nation had the will to fight and a willingness to accept casualties, within reason, in WWII. Part of it may have been witnessing the horrific casualties being suffered in Russia which made ours pale by comparison. And the American press well publicized the terror the Blitz inflicted on British civilians, which thankfully we never had to endure.
Vietnam really seemed to sour the American people's will to endure substantial casualties in a foreign war, but that's another story.
But to go back to the air war, I think we may have a situation where both sides are right. You are correct that the Air Force constantly analyzed film to assess bomb damage and had very accurate data. What they knew but for obvious reasons weren't telling the civilian press is that they considered 20% of bombs in a 1000 ft. radius acceptable and 40-50% quite good. That's in contrast to what civilians were told (who ever said this?) that with the Norden sight the Air Force could drop a bomb in a 55 gallon drum. Hardly. But the commanders believed that with enough bomber strength, which was being achieved in 1944, with that level of accuracy the German aircraft industry and therefore the Luftwaffe could be destroyed. What they didn't count on was the ability of the Germans to repair damage and get back into production, at least in 1944.
In terms of losses, I would say they learned a lesson in the early raids in Germany beyond fighter cover, especially in the Schweinfurt raids, that the losses were just unacceptable. No matter how tight the "box" formation, without fighter cover the losses were too high. As a result, as I understand it, they backed off those deep penetration raids until the P-51's arrived to provide escort to the target and back.
The last couple of days Homer has posted a quote attributed to Goering that once he saw American fighters over Berlin, he knew the jig was up (or whatever the equivalent German phrase). Still, it came at an incredibly high price and you're right the public didn't know it at the time. HALF of the USAAF WWII casualties were suffered by the Eighth Air Force, including 26,000 dead. That's still hard for me to fathom.