Are we drawing a comparison between briefly handling a ball python for basic husbandry purposes and placing it on the lawn to roam around? Apples to oranges. Or are we talking about the people that take their balls for trips down to the local park or pet store? Closer to apples to apples....there is necessary handling and there is gratuitous handling...
Curling up and hiding is not the only sign of discomfort in a ball python. Moving about during daylight hours is also a sign of discomfort.
I handle most of my snakes as little as possible. There are some species that are fairly amenable to it. As a whole, ball pythons are not.