From the picture it looks like centrifugal force is the culprit.
Is this too easy or what am I missing?
What you are missing is that these folks are nuts in a straight descent from Lyndon LaRouche and the Fusion Energy Foundation. According to their view the reason that we have not discovered fusion is a British plot. You see we all follow Newtonian physics, which the British wanted us to do because they then had mastery of the necessary principals of military science and could maintain their empire. If we were instead inculcated into the principals of the Gottingen school of hydrodynamics fusion would be easy - but on the other hand, cannonballs would no longer be confined to their approximately parabolic arcs and the empire would fall.
Continuing the consipiracy started by Newton, the next Blue Blooded co-conspirator is James Clark Maxwell who invented the flawed British version of electromagnetism. If would had followed some other theory of Electro Magnetism we would no longer be trying to understand the dynamics of galaxies in terms of gravitation, however well it actually works for that purpose.
I kid you not.