This.
I think a lot of this dissatisfaction comes down to people wanting to be in control of things that aren't theirs to control.
Seller has something you want, you* see it, you realize you can't have it. You're not in control of that, but your sense of entitlement has just been activated. "It's out there for sale! I "should" be able to buy it!"
Unfortunately, the seller isn't out there waiting for you. The seller's out there waiting for the person who will buy it on their terms, and you aren't in the game. But you know it's out there so it's annoying that the control over all of this is in the hands of someone else.
I hear this underlying subtext a lot in these kind of discussions about what sellers "should" do.
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*You in this case being "any possible person who isn't in the local area" not a specific person.