It's not "short." Gears of War is short. Ico is short. Neither of those games is bad because of that.
Uncharted is roughly 10 hours in length. And, from beginning to end, it's non-stop brilliant game design, beautiful environments, great action sequences, best cover/shoot system out there, and is highly replayable.
It isn't the greatest or most original game ever made, but it's easily one of the most fun and best designed.
9/10