You can actually produce gold :3
I mean btc is all virtual whereas you can physically produce gold.
Ok it's not everyone but you got some jobs that do exactly that!
Well another difference is the potential gain from the investments and assuming that the OP wanted all assets in one currency or another, both have advantages and disadvantages. You're right, gold can be produced but BTC and gold share the trait of being worth what people believe its worth. Owning BTC can be a job just like watching the price of gold, it really depend on what angle you look from, gold may be a bit more stable but it doesn't mean the price cant plummet.
What I'm basically trying to say is that BTC and gold aren't that different and it really just comes down to if the investor is willing to lose his whole investment for a chance at tripling or quadrupling or if they would rather a more stable gamble.