I hope future games as well as other games take note of this.
Not EVERY NPC needs to be as apathetic/uninterested in the player but most should IMO unless you show them you are worth talking to.
He also has things worth saying and learning about so the game actually has you wanting to breakthrough to him, its pretty organic.
A great example IMO as to why he makes a good archtype or framework is because he does something almost no other NPC does in this game or other games. He just straight up lies to you, in a casual way granted but its funny and has people who choose previously selected text options as a habit actually get something out of it.
"You got cigs and tobacco?"
No
*later*
"You got cigs and tobacco"
Ya
"...can I have some?"
no
It really is the little things.