The key here is 'Center of Effort'. Think of the forces of the sail being generated from the geometric center of the sail (not true, but hey, gotta start with something easy with no math..
) If you raise that point up, you are raising the 'center of effort', which means more heeling moment, change in the portion of the hull that is below waterline, how that interacts with the 'center of boyancy', and 'center of balance', etc.
for a reefed main the center of effort lowers the more you reef, which is what you want along with less square footage to catch the wind lowering the power. What you are talking about raises the center of effort, resulting in many bad things.
Spinnaker Sailing Online Sailing Course = Lesson 2
doesn't talk about the center of effort in relationship to the rest of the forces in the boat, but the picture is useful.