My girlfriend works in retail, and every month there's someone who gives her a bad survey because she was following company policy or because the customer didn't listen to her when she was advising them. For example, she worked with a couple to port their phones over from AT&T despite advising them that their phones may not work on her cell network. After all was said and done she got a bad survey because their phones ended up not working well on her network. And her manager even caught them outright lying in the survey about how the interaction went down. She was still punished for that survey.
Customer satisfaction surveys can be a useful tool, but they're often applied as a blunt instrument on employees who have no control over the situation the customer is dissatisfied with. It's basically a lazy copout as opposed to actually fixing company policy. I tend to ignore them unless it's to give good feedback.
A more humane system would take the feedback and then interview the employee in question and their management to understand what the root problem is. But the management organizations that use these surveys are almost never humane. Plainly, they don't give a shit about any of their employees.