Because Far Cry 2 was tedious and boring in a lot of people's eyes. I never finished it myself because dealing with the stupid map, the constantly respawning outposts and psychic enemies got really old really fast.
I love Africa but, in my opinion, they really drooped the ball.
Where were all the animals?! I mean sure you had your occasional zebra and gazelle but for the most part it was dead... They could have had elephants, giraffes, hippos, lions, etc...
I know they said they didn't include predatorial animals because they would hunt you, which is complete BS! They could have programmed them easily enough NOT to hunt you, or only attack when you get too close to them. This is a game after all.
The story was completely lack luster, and the dialog felt SOOO flat it made me want to skip all the story segments.
So far I'm liking FarCry 3, I hope it will be everything we want it to be.