Why was it important to the Framers that the Constitution protect fundamental rights? They felt that the rights they had under the British government should be carried over to the new government.
They felt that their individual rights were not honored by the British government, and they wanted to make sure they were protected by the new government.
They believed the national government should have more power over fundamental rights, so they included them.
They thought the states were not able to protect fundamental rights, so they wanted them included.