I am too.
Oh, you meant humans as the dominant character race in RPGs! I see...
Maybe. But bear in mind that humans are it; they are the be all, end all of races in Golarion. The other races are, psychologically speaking, less alien to the human experience than Ed Gein is. They're all, dwarves, elves, gnomes, halflings, basically human. Even orcs and goblinoids are basically human. They all have a basically human psychology, adapted to the relatively tame variations of their physiology and lifespans.
I have a Tengu PC in a campaign I am running. How do Tengu breed? I don't know. Do they breed like humans? Do they lay eggs? Are Tengu females the larger of the two sexes? I don't know. This is about as alien as it gets, and I could fill these details in myself. But the more alien I make them, the harder it is to explain their integration into human society. The less alien I make them, well; then they're humans-in-funny-suits, like the rest.
That is what they all are; they're convenient in that humanity is a reference point used to make them all understandable. In the real world, we anthropomorphize things all to time to make them easier to relate to - it's a facet of human psychology. Without turning this into a psychology seminar, there's evidence to indicate that other mammals like cats and dogs behave this way as well.
I like having different choices for character races. I'm all in favor of making campaign worlds that are dwarf-dominant, or giant-controlled. I especially root for the orcs to win; they seem like they really got the short end of the stick. The truth is, though, that those worlds are literally only cosmetically different from human dominated worlds; truly alien worlds are much more difficult to come by due to the inherent limitations of human psychology, the pressures of conformity, and the difficulty in achieving a believable versimilitude in such an endeavor. I encourage any and all such explorations, they make for fun games and also make for stronger thinking habits. I only bring this issue up because it's important to understand why a human-dominated world makes sense from both a design and a psychological point of view.