Well the shuttle was impractical in many cases. (Not always, but often). The solid rocket boosters would occasionally fail to deploy their parachutes, resulting in them sinking. The external tank would burn up in the atmosphere, and that is the biggest part on the space shuttle stack. Also, the orbiter has to go through extensive maintenance to be certified for flight. All those components are getting shipped in from the surrounding states (The fuel tank comes from New Orleans by barge). All these expenses added up (even though the massive Saturn V was not much different, no component could ever be used again). If anyone in the US tries to fly into space again, they are going to need to come up with more practical, reusable devices.