My own economic indicators

Something dawned on me recently. Something that's been nagging me, but I couldn't quite put my finger on it. It's everywhere, but so insidious I'm not sure that most folks pay it any mind. Go to Target, or Home Depot, Barnes and Noble, or Best Buy. Publix, SweetBay, or many CVS's. You walk in and do your shopping and when it's time to checkout you approach and lo and behold, there's a dozen, or sometimes even twenty registers and one, maybe two cashiers. I'm not sure what the deal here is. Is it poor design? I've dug deep into the Grumpy memory banks and offhand I can't recall a time when I've seen even half of a bank of registers being used. Did someone overestimate demand? Even during the holidays I can't say I've noticed where they've had anywhere near even 3 out of 4 being used. I'm sure some industrial engineering has determined something about utilization and customer flow and all that, but in reality it seems like a waste of space and certainly has a negative impact on my impression when I walk up to that sea of registers at Target and a single port has the lighthouse on.
Customer service has become a misnomer these days, and this register system seems vestigial, a sign of old where giving prompt service has given way to lower costs and minimizing personnel.