I was in sales and managed sales teams for many years. You can't really understand their perspective until you are in their shoes. It is very frustrating to spend so much of your time treating every customer like gold when 95% of them are not ready to buy and 85% of them probably won't buy anything any time soon.
Since most sales people are paid on commission they literally live for the sale and they can't afford to spend a lot of time on the window shoppers, curious folk, or tech heads which want to hang out and talk shop-tech all day long. The seasoned sales reps have a quick way of sizing up their customers and spending most of their time with the 5%-15% that are ready to buy now or will be ready very soon. Some have better methods than others but none are perfect, and when they misjudge or mistreat a customer then they almost always lose out on the sale but this is still more efficient for them than treating 100% of the customers as ready-to-buy.
Keep in mind that sales people are exactly what we make them. When making a large purchase we expect to be able to haggle on price and negotiate terms of the deal. We insist on being treated special when we pay cash, provide repeat business, purchase a top of the line product, etc. We also want personalized attention and follow-up before, during, and after the sale. We don't act this way when buying a toaster or other low-price, low-tech items which is why most retail businesses don't have sales people. When spending a lot of money or buying a high-tech item then we literally demand the services which sales people offer and thus we have to take the good with the bad.
Rather than fight it you should use it to your advantage. When purchasing my Tundra 4x4 DoubleCab 5.7L V8 Limited just a few weeks ago, I drove down to our regular dealer where the sales people change often enough that we don't have a regular rep. I parked out of site of the dealership so they wouldn't see our fairly new RAV4. I deliberately dressed down in comfortable sweats with a two-day beard to appear very casual and not made of cash. I took the wife in with me to show I was potentially ready to buy on the spot, even though she had nothing to do with the vehicle or my decision. My policy is to give the sale to the first rep that greets us and offers to help since some of them are not even motivated enough to say hello. A young guy greeted us immediately. He was actually standing outside in the rain to get the first dibs on new traffic while all the veterans were huddled inside drinking coffee: I liked his attitude.
Right off the bat I told him exactly how it would go: I had a sizeable cash down payment and was pre-approved for financing. I purchased several Toyotas from this same dealership in the past 5 years. I was ready to buy a new truck within the next week but not on my first visit regardless of what deal he offered. I told him the key to winning my business would be to find the exact truck I wanted, then offer me the best price which I would determine by getting quotes on the same vehicle from 5 other local dealers. I told him I already had all the reports from
edmunds showing the dealer costs, holdback, etc. and that I would allow them a fair but not excessive profit. I told him there was no need for the typical games of copying or holding my license, including hidden fees which show up on the pink slip during the financing, or pulling a bait-and-switch if they didn't have what I wanted in stock. I said the wife was interested and I wanted her to be comfortable in the truck but she didn't really care what I purchased, which she confirmed by adjourning to the lounge for coffee, popcorn, and television while I shopped.
I also told him I would be loyal to him and not work with another rep as long as he was good at follow-up and called me back when promised. This saved us both a lot of time which he appreciated since he now knew how to sell to me and what the rules were.
Right away he showed me a few Tundras and I looked at Tacomas too just for comparison (night and day, not even close). He took me on a test drive immediately without even knowing my last name. We got a price quote from him on the test drive model even though he didn't have the exact vehicle we wanted in stock. This helped us figure out what their starting point would be for negotiations. I left with a brochure, reviewed the option codes and researched model differences online, then called him the next day with the factory option codes for the exact vehicle I wanted. Being realistic I also told him which options I was flexible on: top 3 colors, things I could install later on my own, etc. Turns out he got the perfect truck in later that day so I went back down. We looked at it, test drove it briefly, then went to his desk to haggle price. I had my laptop and a price calculator file which I created in Excel. I just punched in the option codes and it showed me the dealer invoice / holdback and calculated the profit of his offer versus my top price, estimated loan payments, etc. I showed it to him and told him my top price which was non-negotiable. He tried to get me to come up twice and I stood firm. He eventually came down to within $500 but I said I was walking since they didn't meet my best and only offer. They let me walk out that night over $500 which surprised me but then the next morning they called me and came down another $300 so I went in to close the deal, which ended up just $200 over my original price. MSRP was $42,103 and I paid $39,200 which was 7% below MSRP but still 3% above invoice. I felt this was very fair since this specific vehicle was hard to get and 1 of four in my region, the Tundras are still in heavy demand, most other dealers I called wouldn't even come close to the offer price, and some dealers laughed or hung up on me when I said I had a quote below MSRP.
All of this took no more than 2 hours of the sales rep's time and I didn't bug him with stupid questions like "is this the big motor", "what does 4-LO mean", "what is the inner diameter of the spring-shaft-turny-thingy-left-modal-bolt-infometer", or whatever. Anything I needed to know I found out myself ahead of time since I wouldn't trust a sales rep to have all the right facts anyway, especially not the technical stuff on a new vehicle, and because I believe it is best to be an educated customer. The wife and I also spent less time in the dealership and we got a great deal which we feel good about, no stress or fuss.
If you aren't willing to do a lot of the work yourself or you want every sales rep to treat you like gold regardless of the situation then you will have to keep shopping until you get lucky. There just aren't that many out there that are good and treat all customers the same, and the good reps tend to move on due to promotions or better offers.