To reuse a rocket it has to be designed and constructed stronger thus being heaver, more costly to build, launch and puts a strain on payload capabilities. Especially if you are talking single stage to orbit.

Cost is the problem with space planes also, Russia's Buran, ESA's Hermes, and other designs all cancelled due to cost and along with the Shuttle, they are all only partially reusable. Russia's new Kliper space plane is questionable along with its launch rocket. The nice option to the Kliper was its deep space consideration. The biggest con to space planes is the weight of the wings.

SpaceX wants to be able to reuse both stages of the Falcon 9 heavy, but that's a tall order considering the second stage would have to have reentry shielding and they didn't have success recovering the first stage without severe damage with the last launch.