I saw 10,000 BC the other night and really enjoyed it. No, the movie is not a deep cinematic exploration of life, but it is a fun summer-type action movie. I mean, how can you hate a film with sabertooth tigers and giant carniverous birds!
One thing that puzzles me, though, is that 10,000 BC has received fairly negative reviews, with many of the reviewers complaining that the film is not historically accurate. Well, duh. The film even starts out with a voice-over stating that what follows is essentially a myth. But because the film takes liberties with history--nevermind that our knowledge of the specifics of human history that long ago is very limited--the movie gets panned. Now contrast this with movies and TV shows set in current times which take liberties with reality in ways which we know are absolutely wrong. For example, the action scenes and events in the TV series 24 are uniformly unrealistic, as they likewise are in the film No Country for Old Men. But we accept that these are cases where cinematic license is taken with reality in order to tell a compelling story (and in the two examples given, even reward these productions with well-deserved awards).
So my suggestion: Enjoy 10,000 BC for what it is--a far-fetched but fun story--and don't get all worked up over whether or not it is historically accurate.