Customer satisfaction is about as easy to quantify as AHT. We routinely send out surveys to measure customer satisfaction and correlate that information with our productivity metrics and our internal quality monitoring. Yes, high AHT is a problem in call centers, because it costs money, lowering our profit margin. But low customer satisfaction is a bigger problem, because it drivers customers away, effectively reducing our profit margin to somewhere approaching zero.
I understand there are a lot of not-so-good call centers, but the majority really is no longer just hiring monkeys to read out scripts to calling customers. And agents really are not fired just for failing to meet AHT targets.