To me, an offer is an offer. I have no emotional attachment to the sales transaction, so I can't understand (but don't judge) being upset with a 'lowball' offer. The negotiation has to start with a number, so why would I take any risk what so ever of offering something that you might take? Putting money on the table that doesn't need to be there makes no sense to me.
I learned from someone alot smarter than me that you definitely don't get if you don't ask. If I throw out a 'lowball' number, maybe they say yes, maybe they say no (or don't respond), maybe they counter. I assume that if someone doesn't respond or doesn't counter, that they are a pain to deal with and I'm better off anyway. If someone counters with a number very close to their offer price, then I know that they are firm, and I can continue to negotiate, or decide that I'm not willing to pay that price. No harm, no foul.
No expert by any means, but I buy and sell a fair amount of things, and I think everyone benefits when people aren't emotional when buying/selling. For the life of me, I just don't understand (and I don't claim to be in everyone's head so I'm not judging) why I would get upset if someone is willing to offer money for what I am selling. I appreciate their offer, and counter if I don't like it.
Peace and love