Complaint
The villagers were obviously jealous of that handsome pay and they also coveted the knowledge of how to build the Kangs, this skill was only known to the very few people and that too in the capital! Though it was a very rare skill, the villagers didn't doubt Yu Dong, she was someone who has connections with the rich people in the town, so they all thought that she somehow flattered her boss into divulging the information about how Kangs were made.
The rich wouldn't bother to hide such things and would tell as long as they were happy with the services of their workers only those whose entire living was based on Kang making wouldn't let their secret skills divulge. And Yu Dong knew the boss of the most famous restaurant in the town, of course, she must know how to make a Kang!