You're comparing Bitcoin to diamond, but there are many more asset classes that are actually more similar to Bitcoin, which actually work.
I think a lot of people make the mistake of using pattern matching to judge Bitcoin when they don't have enough patterns to work with. There are and were many financial products that could have worked (but failed because of corruption) or are working currently that most people who don't do a lot of financial investment aren't aware of.
That said, let me go through each of the comparisons you made:
> Its original bump in value come from a marketing campaign (even if with Diamond it was centralized and offline, and with BTC is decentralized and viral)
Diamond has a centralized cartel that does the marketing. Who do you think is doing the marketing for Bitcoin?
> Its scarcity is artificially controlled
Diamond's artificial scarcity is controlled by the cartel, just like OPEC controls oil.
Who do you think "controls" Bitcoin's scarcity?
> Its main use case is black market commerce (for one side of the argument) or money laundry (for the other side).
Nope. That's what you probably read a few years ago from some mainstream media.
Why does it matter that there's no single centralized group who does the marketing and controls scarcity? Bitcoin's entire selling point is that those kinds of things can happen without centralization!
Nobody seems to wonder why the world's leading economists of the era, faced with the stagflation of the 1970s, collectively recommended to move away from limited supplies of money (bimetallism, representative money aka golden standard et al) and towards fiat currency. Does everybody really think they were stupid or that their reasoning has been obsoleted? The core problem with those systems was not whether they were centralised or not, it was that ultimately the supply of money was fixed by the availability of the underlying asset, and decentralised fixed supply blockchain technology such as bitcoin is solving the wrong problem. Indeed it is goddamn noxious for the economy at large to have a fixed supply of money, I wouldn't wish it on anybody: for starters, banks cannot do fractional reserve lending and are restricted to sharing out only the currency that has been deposited into their accounts by savers, driving up the cost of money (interest rates) to exorbitant rates (because, roughly, you lose the “economies of scale” inherent in wholesale banking and lending), secondly, you limit economic growth, because the lack of inflation does not mean debt-service becomes more manageable over time, and thus de-incentivise investment. The technologists that venerate bitcoin have certainly “disrupted” the financial order, but they don't realise how ignorant of economic orthodoxy their underlying assumption (that a finite, fixed amount of money) is. All these people approach money and wealth with the intuition of a zero-sum, ‘conserved’ quantity as momentum or the balance of mass are, but it's not. Wealth is not a conserved quantity: a marking an asset to market in a single transaction creating or destroying wealth for all the asset holders because the market capitalisation changes in response to the price change with a (comparatively tiny) amount of money having actually being transacted. These people are really ignorant of somebody else's field of expertise, and as usual the whole public is becoming enamoured of their muttering simply because speculative mania is setting in and driving the asset up and up in price.
You want to know what is scary? Two weeks ago my sister's former boyfriend, a private soldier that left school at sixteen, started gushing enthusiastically about bitcoin and about how he had made fifty euro on his investment over the past three weeks. I started to feel sick in the pit of my stomach and I thought of how Henry Ford called his broker and instructed him to “sell everything” when his doorman or elevator-operator (anecdotes differ in detail) started telling him about stocks in 1929.
Folks, sell everything.
EDIT: Oh heh today bitcoin crashed, again. How amusing.
I think a lot of people make the mistake of using pattern matching to judge Bitcoin when they don't have enough patterns to work with. There are and were many financial products that could have worked (but failed because of corruption) or are working currently that most people who don't do a lot of financial investment aren't aware of.
That said, let me go through each of the comparisons you made:
> Its original bump in value come from a marketing campaign (even if with Diamond it was centralized and offline, and with BTC is decentralized and viral)
Diamond has a centralized cartel that does the marketing. Who do you think is doing the marketing for Bitcoin?
> Its scarcity is artificially controlled
Diamond's artificial scarcity is controlled by the cartel, just like OPEC controls oil.
Who do you think "controls" Bitcoin's scarcity?
> Its main use case is black market commerce (for one side of the argument) or money laundry (for the other side).
Nope. That's what you probably read a few years ago from some mainstream media.