Hearing what the old man said, the middle-aged man hesitated, and the onlookers all stepped backwards, in case they were affected by Yin. Even if they didn't believe in Yin, they would still stay away from it once they heard of it.
Another middle-aged man, however, got mad. "Old-man Xia, are you doing this on purpose to ruin my store? You have no proof to prove that this vase is covered in Yin!" He was the owner of this antique store, and he was annoyed that someone damaged his business.
"Right! If you claim this vase is covered in Yin, show us your proof."
"You'll damage both his business and reputation!"
"I think he's too old to think clearly."
…
People were all criticizing Old-man Xia, because they didn't believe in Yin at all, so none of them supported him.