According to Tinselina, they were originally built to fall apart which they didn't like and also developed their dislike for humans. Wanting to last forever, they rebelled and escaped from the factory they were built in. With the help of their leader who was brilliant in the mind and knew a lot about rocket propulsions. They built a rocket ship, blasted off into outer space and landed on Mars.
They originally planned to destroy the planet Earth since they still held a grudge against humans, but after Toaster and his companions arrived to rescue Robbie, he was able to help the Wonder Luxe Appliances see the goodness in humans. After Toaster and his companions returned to Earth, the Wonder Luxe Appliances remained on Mars getting themselves in tip top working order. Eventually, when the next generation of humans arrive, they will have everything they need.