i feel like i can speak from some experience on this, having come from a bit of a teaching background, and also having gone to one of those uppity colleges that tend to churn out future doctors, lawyers, bankers, and academics.
i know many, many smart and talented people who won't go into teaching, even though they love teaching, simply because it has the aroma of a 2nd tier profession, when compared to how much our society values doctors, lawyers, bankers, and professors. there's both that, and the pay, and the fact that it doesn't look as if teaching has the potentially to be continually creative and dynamic. much of this comes from experiences with bad teachers, especially in middle school and high school (we used to call them "pieces of driftwood" ... and many of them were men).
i mean none of this as an insult to teachers. i know people from both my college and others of similar stature who are, say, teaching public school in the Bronx. they do tremendous work, but they also don't see themselves doing that forever. burnout is very high, and pay and lack of respect don't do much to ameliorate burnout. i'm just trying to explicate the stigmas attached to non-university teaching that swim in the minds of many of our nation's top colleges and universities.
i have a whole host of suggestions on how to improve teaching, but that's too much to go into here.