That is them doing you a favor and saying "Even though this is supposed to be mine according to the rules, I will give you the opportunity to cast lots on it in exchange for X."

You know what common courtesy really is, buddy?

If someone offers you the chance to lot on their orb without any strings attached, common courtesy is letting them lot something from your orb that they want with no strings attached. Unfortunately, common courtesy is rare these days and people just take something for nothing whenever they can get it. Thus people make arrangements before events in order to ensure that some form of equity is maintained.

Common Courtesy:
Player A shouts to give away AF3 feet they don't need.
Player B gets said boots from Player A, and thanks him by tipping him in some fashion, usually 50k or 100k for their trouble.

Common Practice Situation A:
Player A shouts to give away AF3 feet they don't need
Player B takes the feet and disbands, forgetting the guy's name within a couple days and neither paying forward or paying back the favor.

Common Practice Situation B:
Player A shouts to sell AF3 boots they don't need for 50k because no one has common courtesy these days
Player B freaks out, calls Player A a prick, makes a warning thread about them on FFXIAH, and otherwise verbally abuses someone whose only expectation was that people reciprocated his courtesy. He could have just let the chest depop.

People who can only take favors and can never repay them or return them in kind are just leeches on the system.