Again, I think this is a bit of misplaced blame.
Have you not heard of "lean supply chain"?
The bigger the company, the leaner they try to keep their supply chains. In normal times, lean supply = maximizing $$$.
More or less, we see the same thing at MK. WDW doesn't make money off of empty seats. Operating rides and staffing restaurants costs $. they want butts in seats from park opening until park close.
Stores don't make money stocking lots of toilet paper. It is bulky and the stores don't make money off of it, so they don't keep a big supply on hand.