When discussing crypto, a comparison to other imaginary man made systems is more appropriate: spoken languages and religions. These are not limited; if you don't like the one you found yourself in at birth, nothing (besides social pressure) is stopping you from just inventing a new one.
Besides that it is technically difficult to create new elements, you could just declare another existing element (for example lead) as the new gold. Because there are an awful lot of materials on earth, the physical versus non-physical (virtual) aspect to which this argument boils down is of no practical significance.
Couldn't you ask the same questions for gold? I really see no difference here.
You implicitly assume that all profitable things contain some "strength" not found in others. This is not necessarily the case; a good example: https://en.wikipedia.org/wiki/Artist%27s_Shit
If you ask me, the success of an idea or concept essentially depends on the ability to entice a big enough group to support it in the first place. Apart from general marketing methods, for money-like ideas the release scheme is essential: The supply of the virtual or physical object to be used as money must be limited, so a value impression can be formed on the perception of scarcity. Both Bitcoin and Gold have limited supply that is released in a quite predictable manner.
So overall - apart from the virtual versus physical distinction - I can't follow your argument.
ya.ya.yo!