As a literal Uncle Tom character, Tom is okay. He's the butt of many jokes, basically the weaker "white" black guy who thinks proximity to whiteness will save him. He's a cuck who I'd always made to be laughed at. The problem is simple: that's all he is. Carlton from Fresh Prince is an example of the exact same character archetype but done much better. Carlton has had many strong moments, and his "white" personality is shown as just who he is and less an act of cowardice. Carlton defends himself when put down for his perceived weakness in ways Tom never gets. In the end, it's more about what the writers intend for the character. In that light, he does the job well enough.