"I always wonder why birds stay in the same place when they can fly anywhere on the earth. Then I ask myself the same question." - Harun Yahya
"Harun Yahya" aka Adnan Oktar the Turkish sex cult leader? Yeah he stays in the same place because he's serving 8658 years.
This was always a flawed quote because even before such a realization, people still did novel things (and literally flew to new places), much the same as birds. And the answer is still the same for birds and humans, the constraint of resources. If you have enough then by all means, fly.