I didn’t know all that. So, when the phase “Uncle Tom” is used as a pejorative, it mocks and belittles all of the character’s good qualities, which were many.
You should read the book, Uncle Tom is a tragic hero molded in the finest Greek tradition, doomed to his fate, his life is chronicled to it’s inevitable conclusion, it is the lives that he touches along the way that is supposed to give us hope for tomorrow.
Stowe was criticized for the heavy handed way in which she wrote the book, in truth there is a huge influence of the early Greek theater especially the Tragedies in the book.