When the cats were exterminated, rats came and brought in fleas. One of the many reasons the Black Death occurred. Cats ate the rats so without the cats rats came with nothing stopping them.
Millions of deaths
People used to believe that cats were the devils so they started exterminating them one by one.
Shortage of serfs
Why is there only a few of us?
When people started killing cats, rats were accumulating because the cats weren't there to eat them. Known fact is that rats contain fleas. Then, the fleas were causing many deaths but, people didn't know they came from fleas.
Serfs demand a raise
Due to the fleas on rats, death became more and more common. Millions of people were killed.
Serfs become employees
I now make all serfs, EMPLOYEES.
Since millions of people were killed, this also included serfs. More and more died and that left them with only a few left. That is, if they didn't die days after.
With very few serfs, they were expected to work for more than one person. Until they decided to demand the king for a raise. They figured that if they were going to work for more than one person they should also get paid for more than one person.
Us serfs believe you owe us better pay. We are working too hard to be getting paid very little.
Finally, the king decided they had the right to demand for better pay. So, the king made all serfs employees. Meaning that they can demand for things at a certain extent.