I do agree a simple hello to (in theory only) a potential customer is bare minimum manners and human, and doesnt cost that much time. That being said, did this duh have nothing to do while looking at cars that he was paying attention who is and is not saying Hi to his dorky son? If his son loves the cars, he's happy just looking at the cars. Many a modern kid doesnt even want to look anyone in eye let alone an adult stranger. Back in the day, many a kid would be ignored, only the nicest of the nice might interact w/ stupid kid, or only interact to get on Dad's side to make a sale, which would be a lesson in schmoosing, my guess. Anyway, we all complain too much on the 'net and put every little thought out there, and this is just another case of that.
And, you never know, a seasoned salesman may have had learned over the years, that getting in these types of seemingly innocent convos ends up being a big time waste, and distracts them from their real money-making work, or the 'why are you talking to my child!?!?' crap. I know over the years, I changed my habits w/ clients, started meeting them at destinations instead of walking there, wasting time up and down elevators, whatever else, 'oh i have to use the restroom again', getting involved in some convo, dealing w/ them walking too slow or not having their ID when needed, all little frustrations, while not a big deal, certainly made my life a certain small % better not going with them and all that stuff was taken care of without me. Did I lose brownie points I coulda made being more personable in the down time, maybe, or they didnt know the difference. But as I said, a seasoned veteran learns that sometimes, many times even, you can put in 110%, bend over backwards, and the client will still give u a moderate survey review, so what is the point?
I'm not a salesman tho. Their job is personality, but maybe they know who to use it on.