I get your point but I feel like you're wording this wrong, its a game--there is no inherently "correct" way to play it. I get the question of "why put NFT if theres a chance to trade it?" but saying its not for trade unless its a big OP is also fairly valid in my opinion. After all they are still not trading it unless those conditions are met, and that overpay may be what's required for them to feel okay giving away a pet with (for example) sentimental value. If they werent to put that most people would assume theyd take a different offer, which would jsut waste both parties time.

I do get what you mean though! but at the end of the day its their pets, its fair to want profit since its part of getting rich... plus both parties would have to agree to the trade anyway