Wouldn't it be much easier to launch payloads into space. Even without the hub?

Envision a building/platform 50 miles tall. With runways/tracks on top pointing various directions. Ships would take off more-or-less horizontally on the runways/tracks. Maybe they could be accellerated magnetically. They could land at standard airports on earth after delivering their payloads.

There would be extreemly little wind resistence at 50 miles in altitude. What speeds could be attained? Could use the gravity of the earth to accellerate and then skip off the atmosphere to gain additional altitude. (Kind of like your falling into space idea?)

Would it be enough to launch a payload into low earth orbit where it could rendevous with the ISS or another orbiting platform where missions could be launched to the Moon, planets, etc...?