Especially when they're trying to tell you they want to buy a different product that you're selling.
That salesman was operating under the working hypothesis that the customer who entered the store wanted to buy a phone, so he tried to sell a phone.
In spite of a growing collection of evidence that falsified the hypotheses ("I don't care about any of that"), the salesman never bothered to form an alternative hypothesis about what product the customer was there to buy and instead assumed the customer was broken.
What if he would have said to himself, "the things the customer keep telling me are not consistent with him wanting to buy a phone, so maybe he's actually here to buy something else."
After that realization, he might have formed a hypothesis more consistent with the evidence. Maybe the customer actually wants to purchase membership in a club called "iPhone owners". In that case, the phone itself isn't the product - it's just the receipt! Of course he wouldn't care what features the phone has, any more than a movie theater patron cares about the font used to print the tickets.
The real question is: why was the salesman unable or unwilling to adjust his hypothesis to fit the empirical evidence?
Maybe the salesman was operating under the implicit assumption, "If I walked into a phone store, I'd be there to buy a phone, therefore anyone who who comes into this store must be here to buy a phone."
Maybe his empathy or theory of mind is so underdeveloped that's he literally unable to perceive that other people are, in fact, people and just as sentient as he with their own independent goals and priorities.
Without that recognition, then regular customers would indeed look like malfunctioning robots which were not performing their designated function of buying what the salesman wants to sell.
