There is no culture in a world that would consider it normal to run 26.2 miles with no breaks. Walking it in a span of a day is massively different. Anyone who does hiking can do it. The same people however can not run that distance.

Even marathon runners run marathons only on competitions. The chance of injury or sickness after is too high in order to make it worthy. And after, you are supposed to rest for multiple days even if not injured. Again, 26.2 miles is 8 hours of hiking and you are pretty much guaranteed to be ok after it.