The school reformers who would "professional development" us to death would also have you believe that most teachers just aren't very smart. These are the same folks who, rightly or wrongly, put weight in IQ indicators. For argument, let's stipulate that too many teachers are stoopid. Here is a chart showing the population's IQ distribution:
If 100 is normal, and a standard deviation is 15, you see a couple SDs in either direction and you're looking at someone packing, or not, so to speak. How many folks with IQs of 120+ are going into teaching? Not many. Hell, there aren't very many! What might lure them?
Also, I think there are teachers out there who are incredibly smart, and do their thing their way, and it works. They are indeed, and in IQ score, exceptional. So leave them alone! Let them teach! They bring what NCLB is quickly draining from our kids--creativity! Thoughtfulness! Things that matter to humanity, not some bottom line or rung on a career ladder.