There is a huge difference between "this cash in my hand should never go down in value" (which nobody including the GP is arguing for) and "$1 today has the purchase power of $0.05 a century ago is good, or at the very least the natural state of things" (which you may or may not be arguing, but is how I understood it).
The impact of inflation compounds. I won't bother looking up if that 5 cent claim is correct but I did quickly look up average inflation rate, and the average inflation rate from 1941 to 2017 is 3.5 percent per year. Which would mean the value of the currency would halve every 20 years, but that's just how compound interest works, it's not particularly remarkable or surprising.
Nobody complains when compound interest makes their stocks or bonds go up, I don't know why someone would suggest compound interest in inflation rates is some sort of awful social issue.
