Why is that amount any less valid than $10, $14, or $20?
I don't think it's any more valid or any less. It is what Aetna is willing to pay. One might expect that they would attract a better quality of job candidate paying $16 than $10 or $14. And that they think that they can get or retain all the good employees they need without paying $20. It's a reflection of their employment model.