In the case of the US dollar the power of the most powerful and most developed nation in the world is behind it.
The only thing backing the value of the US dollar is a collective belief it will be worth the same amount the next day, the military power and the hell they can exert on "hostile" countries both through military and economic measures. With the latter being in some cases far more devastating and effective in destroying a country from the inside by devaluing its national currency - think Venezuela.
You are right about JK. Being as wealthy and as far down the life road, she has zero interest in understanding or utilizing the value proposition of bitcoin, crypto in general or blockchain for that matter.
Although dinosaurs such as herself and the likes of Buffet and Schiff will never get it - in some cases intentionally as it directly opposes their world-view - all PR is good PR, especially when it's free and coming from highly influential people with massive followings.
The entire industry will benefit from it.
...and the size of their economy and the size of their buyers market and the military and their influence. All of it and many more things i forgot to mention.
Saying that doesnt have value is simply not true.
The same belief applies to Bitcoin or any crypto for that matter. Because of its features you believe Bitcoin has value.
Sure but its not really that position of hers thats unexpected that would warrant articles and opinions being thrown around, its the reaction by the community thats funny.