“It's natural -- not an attack -- to determine the relative status of those in any job or profession in terms of the subset of the population from which they are actually drawn, whether it be high school drop-outs, high school graduates or college graduates. In the case of teachers, the relevant comparison group is other college graduates. If experience from countries whose students outperform our own indicates that drawing from the top rather than the bottom of college graduates makes a big quality difference, why would anyone argue that the bottom of college graduates should do just fine, thank you very much, because they are certainly more qualified to teach than plumbers and others who don't graduate from college?
Arguing for a teaching profession that is more qualified is not an attack, but a ringing endorsement of the importance of teachers to teaching and education to society.
And as for the "that's another story" aside about studies that have debunked any link between SAT scores and teaching effectiveness, there is indeed another story -- the factual one. In fact, there is a clear link between SAT scores (as well as ACT scores or any test of a teacher’s vocabulary knowledge) and teaching effectiveness. Individuals with strong academic aptitude are more apt to be strong teachers, a fact that school districts have long ignored at children’s expense.