For more than a year, FOB players and Story players have used save editors, usb re-uploads, and other methods, to stock up on depleted resources. This only worked offline.
I suspect, the main reason for making the game online only, is to regulate and restrict those users so the rest of the community cant complain about cheating. But... youll complain about it being online only.
Its a double edge sword for a few, and pick your poison for others. And considering what the general public thinks of Konami, even though theyre trying to change their image, theyll get backlash no matter what they do/say.