I used to be guilty of this by accident. I did not even realize I was doing it until a player said something along the lines of, "I pick up an extra 50' of rope. I ignore whatever jerk thing the shopkeep says." Ultimately, I had not realized in trying to give my NPCs personality, I was always sort of defaulting to the "suspicious stranger" archetype and its variants. Once I realized that, I have made a strong effort to vary up my NPCs and their reactions to the party.I had a freind who was otherwise a pretty good GM, except that almost every NPC was a jerk to the PCs. They were almost always hostile, obstructionist or unreasonabley suspicious.
This was regardless of your PC's level of charisma or similar social aptitudes.