Why does Aristotle reject Plato's theory of forms?

Aristotle rejects Plato's theory of forms because he believes that forms are immanent in the physical world rather than existing in a separate realm. He argues that true knowledge comes from observing the empirical world, not through the contemplation of abstract forms. Additionally, Aristotle criticizes Plato's theory for being too speculative and removed from the practical concerns of understanding the natural world.