I really don't think many people would even think about that other then when they are cruising. Many people would never be able to go on vacation if they had to think about having $8000 for medical transportation set aside to be transported home during the SLIGHT chance something may happen. Sorry I don't know the situation at home with your in-laws but you sound very bitter and unrealistic.
Quite the contrary, if you are traveling a long distance with an elderly person with perhaps known medical conditions, it is very realistic. Sniffing the fairy dust to the point where at least one person isn't dealing with directly with reality is a recipe for disaster. I am saying that you need to consider the probabilities involved. I even consider it when we go, but everyone in our family is in good health, so the probability is fairly low.
If there are known conditions you had better consider the probabilities, or you are going to be faced with a rather large bill unexpectedly. One poster has mentioned travel insurance. That works, but generally pre-existing conditions are excluded, so would have been of no use in this situation. Believe me, insurance companies know a bad risk when they see one or they wouldn't stay in business. Note that I do now get travel insurance for myself and my family when we travel, just for peace of mind.
The take away points here are that one naturally needs to (honestly) assess the nature and severity of any medical conditions, recognize that travel is stressful (which was a factor in MIL's instance), and that medical transportation home is probably going to be very expensive if it becomes required. If you are still comfortable with the risks, both to the individual and finances, then go for it. But just make sure it is an honest assessment, and in the worst case make sure that you understand you are potentially risking someone's life for a couple of days in Disney. Yeah, yeah, I know: life is a risk blah blah blah. But probabilities change depending on circumstances... as the travel insurance companies are well aware.
One more thing: our family's experience with the local hospital was less than wonderful, but there were also possibly some mitigating circumstances. Suffice it to say that if there are known conditions, it might be helpful to have some form of medical records immediately available. I don't know how that works or if there are such records you can get for such purposes, but in our case there were complications because of incomplete information. Perhaps others can provide solutions.
You may refrain from flaming as well, or trying to assign this to some sort of faulty mental state. I am simply trying to give the original poster some food for thought based on our experiences. They are free to consider it or not.
Regards
Gully