1. It's silly
2. It's hilariously stereotypical
Jackie's uncle, appropriately named "Uncle," is a stereotypical Asian old guy. His catchphrase, "one more thing," is highly quotable. He also has a sassy niece from China. All of the artifacts that the show centers around are based on some vague, unspecified Asian culture.
3. The villains are dumb
The villains in this show don't stand a chance. They don't stand a chance and they know they don't stand a chance. They always attack and then Jackie Chan starts kicking their ass and then they give up and run away.
4. This song.
To play us out...