The answer is, I don't know. I don't know why salespeople think that speaking to customers in a preschool-teacher voice is going to make you more comfortable with our answer to your question "where are the neon blazers?" But we do. So we keep doing it.
This voice change isn't meant to be condescending, nor does it come from a place lacking sincerity -- at least not for me, anyway. I love helping people try on neon blazers at Shirt Folding Store. Even if you're one of those people who came in last weekend looking for green crap specifically to wear/vomit on for the binge-drinking St. Patrick's holiday, I still would gleefully help you find a bright green blazer. (Though I might harbor some resentment over your turning my five generations-ago Irish heritage into a series of jokes involving kissing, ass-pinching and puking.)
Even the dudes I work with do it. Don't believe me? Step into the fitting room of a giant corporate fashion retail chain store in anymall, USA, and you'll hear a grown man say to another grown man, "I'm so sorry, but it looks like we're out of your dad jeans sir, um-kay" in an abnormally coddling tone. (It's just as creepy as when I do it, except I'm usually talking to other female customers, and they have more experience interacting in fake voice world.)
My coworkers at Shirt Folding Store and I have discussed our vocal affectation at length, and can come to no logical conclusion regarding why it happens. It's like a force outside of our control takes over our bodies and speaks for us. And speaks in a tone similar to a dog whistle, as if our normal voices cannot be heard by the consumer unless they are in any annoyingly high register. Does it stem from a virtually non-existent desire for us ("us" being mostly single straight women and single gay men) to come off more feminine and/or motherly? No way, dude.
The only motherly instincts radiating off this staff of mostly self-centered me-firsts are possessed by the actual mothers who work there, and even they don't have time to coddle strangers. They're too busy folding shirts, tucking price tags and commiserating about the break room's new trash=can placement. (FYI: The trash can has been moved directly under the microwave now, to keep all eighty of us from overfilling it to the point of no return and then refusing to take it out like the bad roommates we apparently all are outside of Shirt Folding Store.)
I read an editorial recently written by an American woman who moved back to the States after living in Paris for a half-decade. One thing that struck her (and that she didn't miss when living outside of the U.S.) was the fact that salespeople here won't leave shoppers alone. We're overly friendly, touchy and pushy, apparently. That struck me as odd, considering the majority of people I help with cardigans and polos not only want my help, they want my undivided attention. Sometimes they even interlock their forearm with mine -- without consent -- as if to keep me from walking away from them. (Which mostly weirds me out and makes me wonder if they had a traumatic experience in the past where a salesperson left them in a field or at the bottom of a well to starve to death, or something.)
But as I continue to stumble through life, answering phones and fitting room quandaries with a voice I've never heard come out of my mouth other than when operating the mothership of Shirt Folding Store, I will ponder this vocal uptick. Just know, I'm never trying to sound like a jerk. That's just the way I talk. To you.And, high-pitched voice or not, at least I'm not this asshole: