There are many people who have a social dislike for haggling for anything.
There are many places that offer used merchandise for a fixed price that people shop at, flea markets are fairly unsuccessful in the market for used merchandise. There are many stores that sell jewelry at a fixed price. Stories about people groaning about bidding wars on homes are ubiquitous. And some sellers don't negotiate.
Consumers are consumers, and some cross-section of them will always lack negotiation skills and/or have a distaste for the practice.
Maybe I was a little too strong by saying no one complains since I have not discussed haggling with the entire population. Put simply, I hear people complain about car haggling but not haggling for other things.
As far as you thinking not any of what I said is true; I think you read a whole lot more than I wrote.
People often do want those things.
You do realize the “diamond paint protection” and the other 1000-$2000 of crap on a modest car is all fake — not even from the manufacturer. It’s just gravy after their commission is already baked in.