Why it is hard to imagine humans living on exoplanets

An astrophysicist named Michel Mayor, who was awarded a Nobel for discovering first planet outside of our solar system. He discovered it in 1995, and since then more than 4000 exoplanets have been discovered. Distance to reach the nearest exoplanet is 70,000 times more than distance between earth and Jupiter. We may be able to send astronauts to Mars in next few decades but distance to Jupiter is even more. Currently, efforts are being made by several nations to send unmanned spacecraft, so it will take significant time to send astronauts.
As we are destroying the earth many scientists are suggesting to move to another livable planet but going to exoplanets is not an option at least in the near future. Mayor received the Nobel award as a co-recipient with Didier Queloz and another half of the award was given to James Peebles for exceptional work in dark matter and dark energy. Even in an optimistic scenario, going to exoplanets and leaving the earth is hard to imagine. Another professor of planetary astrophysics at the University of California agrees with the Michel Mayor. He stated that he would be surprised to see if we could go to orbit of Jupiter in the next century.
Some people say that many things we have achieved now were not even thought of earlier but we still made it. It is difficult to imagine it in this scenario as the fundamental understanding we currently have of mass, energy, and acceleration is not enough to travel to exoplanets. It would require fundamental change in the understanding we presently have about relationships between mass, acceleration, and energy. Andrew Fraknoi who is chair of the astronomy department at foothill college insisted that he could never say it is impossible as evolving technology may make it possible but after a long period of time.