You are absolutely correct. Oil in the bearings will increase stiction and can even degrade the sound substantially at worst. I have no issue if Raul thinks that the FR64S is the worst arm he has ever heard in his system. However as you point out he cannot possibly ascribe the poor results he has experienced in his system to an attribute of the arm unless he has deconstructed the arm and run extensive lab tests trialling changes to the arm and measuring the results to isolate what each component and design element within the arm is contributing to any resonances generated by the cartridge on playback. Even then, the results can vary depending on cartridge, set up and arm board termination. Rauls' observations are only relevant within the context of the system in which has has heard the arm. He does not seem to grasp this concept and continues to make sweeping conclusions as you have alluded to.
With my Naim Aro the arm tube is purposely undamped, the designers intent is to transfer resonances as fast as possible to the unipivot bearing, where the bearing design and low centre of gravity from the underslung counterweight are designed to add mechanical damping by about 6-8db, from whence the residual is sunk to the arm board via mechanical grounding..