Reminds me of classifieds like "will sell for $100. Serious buyer will get $30 discount".
Local stores are not all the same, of course. Some, perhaps many, local stores don't deserve to survive. They are poorly run and perfectly willing to scam people who don't know the market price of stuff. But still I'm eager to at least try to work with them to avoid living in a world of nothing but enormous, monolithic corporations. Granted retail isn't exactly my favorite industry - I'd much rather support small makers of things - but I still try.
The only reason I can think for someone to like haggling is it lets them think THEY got a good deal, and makes them feel better about themselves. However, it is almost always in the interest, and benefit, of the seller if haggling has to be done (they have more information than you do, unless you're willing to spend a lot of time and effort).
Gas and milk, sure. But lots of people still buy clothes from places where haggling is acceptable.