I went to the same barber from when I was a teenager until I was 25.
I was happy to talk to him, because he was familiar; his barber shop was walking distance from my home, and I would regularly walk past because it was along the way to where I was going.
Since I moved from my childhood home I have never replicated this rapport, or desire to talk to the person cutting my hair.
I often get my hair cut at a discount barber - because it is cheap, quick, easy, and familiar, but I still find it uncomfortable when the person cutting my hair tries to engage me in conversation.
Recently my wife started having a hairdresser come to our house to cut her hair, and I decided to get a trim whilst she was here.
Because she was in our house, was familiar, and had become a friend I was able to talk to her as she cut my hair.
I guess it's an aspie thing; though maybe effects us to varying degrees; but I just don't feel comfortable having conversations with strangers, or getting pushed into participating in small talk.
I would say it's partial social anxiety, and partial not wanting to enter into a conversation with someone else who has their own agenda and interests driving the conversation.
That said, if I had someone try to strike up a conversation and the subject coincided with one of my interests, I'd find it hard not to talk.