Up here in Seattle the glut of open tech/programmer positions are at Amazon. I don't know if it's growth or their "bar raiser" policy slowing down their hiring.
I imagine AWS is one big firefight, and it probably outpaced their retail business long ago. That's from outside observation, mind, and it's a guess (but an educated one).
They might be hiring at a normal rate but unable to keep up with operational demand -- which is a real pickle of a spot to be in -- or you're right, they're too choosy. I sincerely doubt there's a shortage of folks to work on Amazon and AWS.