Clarrie
You should also consider the cost of not uplifting xxxxkgs fuel at the destination airport when fuel at that point is less than it is at the point of uplift. True, the opposite may be the case but as I understand it, the cost differences are often revealed in the FPL so as to provide guidance to drivers.
PM
I know of the 'pressure' to which you refer but it's really only applied in the cause of an efficient operation, diversions notwithstanding. I suggest that if it ever became common knowledge that management at any level or in any part of a company was reprimanding pilots for, or tried to interfere with, the way in which they exercised their operational prerogative, then that management would be outed in more ways than one. That said, there's nothing quite like a conspiracy.
Blogs
Betcha can't demonstrate that the bean-counters do it! Analysis are made as to variations in fuel prices. Graphs may be produced showing 'excess' fuel uplifts etc etc but has anyone been actually reprimanded, counselled etc for boarding xs fuel?