I agree. Trying to think of why, I think I often see it as a reflection of dishonesty on the part of the seller, or aggressive behavior on the part of the buyer

I agree. Trying to think of why, I think I often see it as a reflection of dishonesty on the part of the seller, or aggressive behavior on the part of the buyer. If a seller can't set a fair honest nominal price, in the expectation of haggling, it reduces my trust of them in other ways. There are situations where negotiating makes sense, but often sellers should assume their list price is what they've negotiated.