This actually feels more plausible to me than colonies on Mars, to be honest. The delta v to get materials from one place to another in zero g is much smaller,

This actually feels more plausible to me than colonies on Mars, to be honest. The delta v to get materials from one place to another in zero g is much smaller, so travel between cylinders would be pretty cheap, and solar panels would be easy to make thin and cheap too. Mars on the other hand has all the disadvantages of being in a gravity well but without the breathable atmosphere of earth or mineral wealth of the asteroid belt. Worst of both worlds.