Yep, they do real great on land, in shallow water, in fresh water, and in the air. They also survive well on plankton, shrimp, carrion and plants.
Not sure of your point, but why would a shark or natural selection care if it can survive on land or in the air? Sharks do just fine in the seawater, which is their environment and they are well adapted to it. I don't think it's purely accidental that life became complex and adapted to species in the air, land and water. Life seems very resilient, not random. It exists in all the most extreme environments on Earth. Why? Why didn't the first randomly created single cell organism just die, instead of spreading everywhere in greater complexity and eventually reading and writing these posts on the Internet? Science doesn't want to know why, they don't want there to be a why, because that explanation starts sounding like a God. But that aversion is not scientific any more than a creationist's aversion to an older Earth.