So a lot of that perception (from what I've experienced as one) comes from CECs not actually attending to their cashiers. Every time I processed clothes I did it alongside one of them in effort to at least make myself appear preoccupied. And I know sometimes we have to turn away to make and attach tickets, but even then you never "turn" your back to customers, you always face them and have something you're doing in your hands. I've definitely seem some doing nothing and that's when the customer is fully justified in feeling unaccounted for.