Information asymmetry. Loyalists know that they are loyal to their country, but the emperor doesn't. Because there were traitors in every dynasty, the emperor was afraid that the traitors would succeed in rebellion and overthrow his own dynasty, so he had to suppress all powerful ministers, including not only loyalists but also traitors, when it was impossible to distinguish between loyalists and traitors. It is said that manslaughter 1 thousand is better than letting go 1 thousand. It's also a bird trying to hide its bow, and a rabbit running dog cooking.