"The Great Dao is Simple means to have the ability to simplify complex problems and grasp the main contradictions when looking at problems.
The big Vs who sell courses or collect group fees will tell you that there is no such thing as the Great Dao, and all the Great Daos are simple are deceptive.
This is to complicate simple problems, so that you feel that they are very profound and there is something to learn, so you pay for the course."