they will have to start treating their guests more normally at some point.
I think you underestimate our insular mentality and the degree to which we believe in American exceptionalism. Only 30% of us even have passports, despite the 2007 change that requires us to present them every time we re-enter the country, even if we just visited a neighboring nation. And regardless of whether it's true or not, I'd wager that most Americans would believe that the tourism taking place within or between states far outweighs the 80 million visitors that come to the US for tourist activities each year.
On the flipside, I think you also overestimate the typical person's level of care about any of this stuff. I've opted-out of going through the body scanners every single time I've gone through an airport since they were introduced, but in all of those trips, I have yet to see anyone else do the same. While you and I might view this suggestion as an abridgement of our rights and a gross invasion of privacy, most people won't give it a second thought, simply because they've already made their vacation plans and a question on a form about something minor like that isn't enough to put them off. I wish it wasn't so, but we both know that to be true.
The fact that international tourist visits to the US have grown in the last few years (only France receives more tourists, but we bring in nearly 4x as much tourism revenue as they do, and nearly 2x that of China, which is the next closest in terms of revenue) only provides evidence for the notion that these draconian measures haven't adversely impacted the industry.