Mars and the Moon

Steven Hawking recently said that we should begin to colonize the Moon and Mars. He wants the world to give 2.5% of all the money it makes per year to fund the development! I'm no where near as smart as Steven Hawkins but I believe its a lot more worth while to develop orbital space colonies. Orbital spaces would be much cheaper to build and maintain because they would simply orbit the Earth instead of having us fly millions of miles through space. This would also make transportation of materials from Earth much cheaper and more efficient. Also we could create artificial gravity much easier by simply spinning the colonies and using centrifugal force to create gravity. This would also create seasons in the colony similar to Earth. Also because they're pretty much the same distance from the sun we would not have to worry about solar radiation and could grow the virtually the same plants as on Earth as in the colonies. Not sure if Steven Hawkins knows something that I don't but orbital spaces colonies seem like a much viable option to me.