You made your career choice, Joe
...so if you are happy putting in some hours while on vacation because "you are your own boss," good for you. However, there are a great number of Americans who get little downtime as it is, and they neither want nor need to be tethered to their jobs and to their bosses 365 days of the year.
There is a reason why America leads the world in deaths by heart attack. We think it is a badge of honor to die for your employer. Too bad that your employer will most likely be looking for your replacement two weeks after you die (or even more likely that he will just spread out your work to your already over-loaded colleagues), while your loved ones are still grieving your loss.