People don't know how/want to haggle. They can't be bothered beating round the bush, and want to pay as little as possible, but they don't want to insult you by offering something so low that you will flat out reject it.
Alright i get that, but here's my perspective on the matter. (After writing it i fear it may seem insulting but please don't take it that way, it's simply my opinion using your words)
People somewhere along the road just flat out forgot how to haggle properly. The reason we should be haggling is because we're unhappy with the price that the person is offering, therefore we should propose a price we are happy paying and that should be it. If it's rejected then it shouldn't interest you anymore because it'll be above the price you're happy paying.
Now that said, i know lots of people tend to haggle for the pure sake of just saving a couple bucks for no real reason which i guess is fine but this is what makes the haggling process become "beating around the bush" The only reason it became that way was because you never made up your mind about a price you wanted to pay, instead you're simply chasing a unclear goal to save those couple of dollars.
If you're trying to buy something you wouldn't be able to afford anyways then insulting people with a lowball in the end really won't do any harm to you but if someone is desperate or simply doesn't care then you'll be able to buy that item at steal and be happy with that.
*edit* i just re-read the quote and realized i missed the first half of it.....
Anyways, i suppose if they don't know how to haggle then that's obviously something they're going to have to learn and by asking "what's your lowest price" then what they've learn is incorrect but only because someone else taught them that and they taught them that because it worked.
Now do i have a solution for this? absolutely not as i don't know where to start on changing something that this on such a large scale and can't be bothered to do so but i have in the past simply replied with a quote and "i hate this question, please send me a price you're happy to pay instead" or just simply ignored the message completely.