The reason a lot of people have bad experiences is that they're trying to buy something that they can't really afford, they need financing, and have a trade-in they want to be worth more than it is and the whole transaction becomes this complicated shell game.
You just described less than 1% of car transactions.
Sure you can and do have no haggle dealers who could offer take it or leave it finance options and trade ins. But I wonder how many mainstream car buying customers would consider that an improvement when told "that's what the car costs. Sorry if it doesn't fit your budget."
ADDED: I'm sure the experience of buying a Tesla is nice. But it's nice in the context of people who are not going in with no dollars to put down who want to find a way to get themselves into a Tesla.
Of course I should probably just lease a car but that is not very common where I live and thus prohibitively expensive. But I'd like to see it become more common as right now the risks and costs are quite hard to calculate.
I've never bought from them. Last few cars I've bought from private sellers and I will never go back to a dealer of any kind again.
Their prices are generally a bit higher than an equivalent car somewhere else; that's the price you're paying for not having to concern yourself with haggling.
If they just offered one model that has everything and you pick the color, pay a monthly fee and they'd take care of the maintenance, insurance and whatnot.