I think that part of it is that number of calls is the only quantitative KPI that can be relied upon. And not only do talented people not like to stay in the callcenter on the phones, talented managers also don't want to manage callcenters (very high staff turnover, cost-center department, not much sense of achievement when you solve problems, no political power to change the company's product when it's causing problems, etc). So the talented people cycle in and back out for the most part, and the less-talented people remain.