I've been thinking a good amount about such thoughtless behavior after reading several books about sociopaths. Among the things I learned was that sociopaths and psychopaths worm their way into positions of responsibility and authority. Such positions make it possible for such people to remain hidden while creating havoc on those around them. The most recent and extreme example is that of a German nurse who was charged with murdering scores of people. A well known example is Ted Bundy who was an EMT. Sociopaths seem to be a less extreme version of similar behavior and the common thread is lack of empathy.
According to psychologists who study the condition, about 3-4% of the population are sociopaths but their positions of responsibility and authority produces more mayhem and confusion than their actual numbers would indicate. Another milder example, one we are more familiar with, is the individuals who delight is derailing threads on internet forums but do not add any useful content to the thread itself.
Having said all the above, most of my own experience with medical people, but not all, finds them professional and caring.