What's the difference of particles appearing and dissappearing in ultra-high-frequency around us, and leds on our monitors switching on and off every xx Hz ? We assign value to both, don't we.
Precisely.
Gold has been preferred traditionally over other states of mass as physical store of wealth primarily because it is a very stable element.
The properties of gold that we desire, its physical beauty, malleability, weight, corrosion-resistance, etc. are all backed by mathematics, physics and electromagnetism.
Gold has its merits. But these days, there isn't enough of it to go around when used as a general medium of exchange, and its ex-changeability is questionable (few people will accept gold as payment).
What if there were an alternative, stable store of wealth and medium of exchange worthy of the information age, stored in digital form, also backed by the physical properties of the universe?
The culmination of technology is currently the information age. Why shouldn't the culmination of currency be a an info-currency, or bit-currency (bitcoin). The internet and computer systems are now sufficiently stable and redundant that we now can be virtually assured of bitcoin surviving anything but a world-ending apocalypse.
Satoshi is a genius.