Gold is *naturally* money. It's not something that humans had a say in. The best way to understand this is by the anthropic principle - what else could be money? There is no other substance with all the right properties. Silver, platinum, and palladium are the runners up - but they lack better identifiability, since the grey metals all look pretty similar.
The cultural significance and beauty were probably assigned after humans came to recognize it as a store of value. For example, aluminum was once highly valued due to its near non-exsitence in nature in its elemental form - more valued than gold even, until we figured out how to refine it. Bitcoin doesn't have aesthetics going for it, but it doesn't have to. Plenty of people think stocks and bonds are valuable for example, and there's nothing pretty to look at there.
So bitcoin has all the necessary monetary properties of gold, with the added advantage that it can be moved around electronically. So I would say it's actually far better money than gold (at least as far as market participants would be concerned - governments hate it). Yes there is a chicken and egg hurdle before it can gain widespread adoption as currency, but actually there is a plausible path to get it there. Already as I mentioned it is perfectly useful for foreign exchange including international wire transfers. This doesn't require it to have a particularly stable value as long as there are currency exchanges available to both parties. Money and currency are not the same thing... bitcoin is already money, even if it's not yet currency.
Why couldn't they be exchanged for goods and services? Sure you start with currencies because they are the most liquid, and bitcoin has a very speficially compelling utility in that it can be used for international transfers outside the banking system. However it is already finding uses apart from currency exchange.
As far as being otherwise "worthless" - the same is true of US dollars with one critical distinction: the value of bitcoins is set by the market, whereas the value of US dollars is dictated by fiat. Do you understand the difference? Nobody would accept US dollars were they not legally mandated as currency. Oil producing nations would not accept dollars unless we held a gun to their heads.
By contrast, the value of a bitcoin is decided only by the parties to a trade. And nobody can make more of them without incurring the expense to mine them. That is what makes it "sound money" like gold or silver. Except unlike precious metals they can be moved electronically.
It astonishes me how much people love to rip on bitcoin without understanding really the first thing about its purpose.
To put it a slightly different way, if we must be legally coerced into using federal reserve notes then we are not "willing to trade in it" - we are being forced to recognize value that the instruments would not otherwise have. Do you see the difference?
Bit coins are only as valuable as the economy that's willing to trade in it.
This is a desired characteristic of sound money.
100 oz bars have been counterfeited but would fail even the most casual test - just weigh and measure to check density, or compare to photos available online. Better to use an ultrasonic tester which is something a silver dealer should be expected to have.
"When the going gets tough, the tough get empirical." -- Jon Carroll