Why do so many sellers take offense to offers on their listings?

agree this is a nice thread, speaks to the psychology and mindset of various buyers and sellers in our hobby, where used gear is a lifeblood for many who seek to experience different equipment at an acceptable cost

i personally don’t attach ego to selling any gear... you are a seller looking for a buyer, and thus welcome all interest - different folks approaching with different methods and tone of communication get different responses, some more friendly, some more terse than others - i do try to remember buyers are also audiophiles and we come in all different ages, backgrounds, experience levels, some have more money than others, some have more fear than others in buying used

i have also lived in cultures where haggling is pretty much a ritual on any meaningful purchase... so while i personally don’t care for it, i accept it as a necessary evil, if you want to sell something, you gotta play the game, even if you don’t have ego wrapped up in the sale, maybe the buyer does in his purchase, so maybe you give a little try make him/her happy?

but in general, i do as @lalitk says, on any lower or 'lowball' offer, i state what i am willing to do, and then wait for a response

When I see the phrase "Make an Offer" my interpretation of that is the Seller is attempting to encourage dialogue. The person wants to sell the item, knows that it is used, but feels that his item deserves consideration at a specific price but is also open to considering another price.  I see noting wrong with this.  I take no offense when I receive a price that I think is too low.  I have sold at least 2 or 3 items where the buyer started out lower than I expected and we were able to eventually come to an agreement on a price that we both felt was fair and we completed the transaction.  Its called Negotiations.  Neither party gets exactly what they expected but at the end of the day each agree on a price that they both are satisfied with.  

well said