What a lame argument. No, teachers don't enter the profession for "the big bucks", so Coulter's conclusion is invalid. But it makes for a great punchline, doesn't it?
I urge you to read her book
Umm.... no, thanks.
If you enter teaching to get the big bucks, be sure you get into administration or into coaching. Let me modify that: Coaches really don't make big bucks until they go into administration, which is why 70% of administrators in Texas are ex-coaches. Administration is the last refuge of a losing coach.