Except I wouldn't call that a bias. Bias is prejudice, and in this case would mean something like hiring people for certain characteristics that are irrelevant w.r.t. to the job. Even where ethnicity and race are concerned, it doesn't necessarily imply bias. If, say, a black social organization only hired black people, it wouldn't necessarily be biased. Why on earth would they hire, say, white people?

If you were starting a company and you wanted to attract people that value education and want the best for their children and see SAT scores as an indicator of quality, then yeah, you'd do exactly something like this. There's nothing immoral about it, unless you want to debate the effect Amazon will have on the town. What's immoral is the weird guilt and self-flagellation involved in thinking there's anything wrong with it. Who gains exactly from plopping Amazon HQ2 in some shitty town?

If there's anything I worry about, it's the growth of Amazon and its bed fellows.