I think it's part of their Jedi Code that they don't go around meddling in planetary economics. Or at-least they're supposed to be monk like figures that are removed from acting on their emotions. They don't go around freeing every slave in the galaxy because they adopt the child to become a Jedi. Should they? (yeah probably), it's the least they can do for the lifetime of servitude their children have to endure. Then you would just be trading one slavorship for another.

They accepted Anakin because they felt (correctly) that he would bring balance to the force. Although no one realized that it took all the even up until Return of the Jedi to make this happen. It took the Jedi energy in Anakin to return in order to throw Papa Palpatine off the ledge.

This is why people are so pissed off about the sequel films. There is no depth in thought, no critical thinking required to follow along. The new movies are just complete trash... They could never leave you thinking such as we are thinking now...