Oh, my rapidly spinning head. I'm noticing beamMe (as a Star trek fan) stating 2001 should be required to explain itself and wipe out all mystery. Then, the statement that 2001 doesn't appeal to non-genre fans. As Alan Arkin once said in 1966, I disagree most veegorously.
I think it's some of STAR TREK
's episodes that should attempt to explain themselves, starting with THE CLOUD MINDERS and THE WAY TO EDEN. TREK sometimes spells itself out too much. That's often a curse of series television. 2001's explanations are already there for us to see, using our own interpretations, if we wish to see. But if you still are wanting in meaning, watch the decent sequel 2010, or better yet read Arthur C. Clarke's tie-in book or the Marvel Comics oversize treasury edition. They are the Cliffs Notes versions and the tie-in novel at least is highly available.
I don't think 2001 is pigeonholable as a genre-film at all. It transcends its genre as Kubrick usually did, and can easily appeal to non-genre fans and movie critics who would have normally thumbed their noses at sci-fi. Granted, it didn't get the Oscar nominations it could have, but leave it to the Academy to be behind the times.
I consider 2001 to be the 12th best film ever made, three notches above JAWS and five over STAR WARS.