Why cant we get off this damn planet?

Gravity, no one wants your ass in space, you don't do enough meditation, asking retarded questions, wasting time thinking up stupid questions to ask, not hitting your library in order to find out that your questions have been answered by something called NASA...decades ago infact, gravity, stupidity....

Pick a reason.
Ever fly in a plane? That will get you off our planet for awhile at least.

If you mean like traveling through space then consider this, there's enough radiation outside our atmosphere that within 3 to 6 months you'll be contaminated with enough radiation to die a very slow and sometimes violent silent death. They have not solved the problem to shield humans from this dangerous type of radiation well enough as yet so we are staying here until they do.
If you can get off to Latvian midgets and this thing called tentacle porn, you can get off the planet.

We could probably throw all the 1st Year students into space...