Clearly not all of the people keeping an eye on his factory were guards sent by the Fog House, as there were a few trying to find out what this place would be used about, and its owner.
It was logical that many people would get curious about the new arrival and his intentions, as this was the industrial zone of the City.
Which of the people owning a place or a factory in this place weren't wealthy and influential? Furthermore, this was also a way to prepare for possible future competition.
They would rather destroy the bud before growing, than sharing the land, water, and minerals once it was grown. No one would be willing to lose a part of its pie, no matter how rich he or she was.
Roy was no different, if he had the chance or the opportunity to get rid of the competitors he would surely do so. After all, in monopoly he could place the prices however he wished.
