Surely it is applications. When I think about my tech friends and family I can think of few applications of cryptocurrencies that appeal to their needs. When I think of my non-tech friends and family the existing applications are far far inferior to centralized applications that already exist.

Why would my grandmother use bitcoin or any of the other applications built on blockchains? Stability doesn't matter to her. What matters is that there is something that it can do that she wants and current solutions cannot do well. All bitcoin does for her is instantly destroy her money when she inevitably loses her private key.

Because cryptocurrency sounds like a scam?

Seriously, from the outside, a bunch of people with no standing whatsoever created a bunch of numbers on their graphics cards and call it currency.

Now, compared to fiat currency, which in most cases is backed by a government with a long history, cryptocurrency sounds like a scam.

There is a vast difference between a government saying something has value vs. a bunch of random people and an obscure Japanese guy (who may or may not even exist) saying something has value.

Fiat currency has some measure of stability. If a gallon of milk costs around $4 today, it will probably cost around the same tomorrow. Can you say the same with cryptocurrencies? And which one?

Just to clarify, what do you mean by "Crypto"? Is it Cryptocurrencies?

Why would the average person trust a bunch of cyber-criminals versus a bank?

How do I know the crap I download isn't loaded with keyboard loggers, trojans, etc.

And before you say well, you just compile .... you lost the average person at....

the best use case in the united states is as an alternative to gold, as in store of value. that is crypto's killer app. the payment system cannot compete with centralized ones, unless you're looking to buy black market goods.

financial products like ATM's, credit cards were very slow to achieve widespread adoption. like a decade each.

its possible consumers will start buying a bit of crypto instead of lottery tickets. thats the only way i see half the population using bitcoin/ether/etc.

It is widely adopted. HTTPS, whatsapp, password hashing, etc.

There's a lot more crypto that could also be widely adopted, e.g. pgp, encrypted dropbox-like-things, encrypted filesystems, etc. Generally I think it's a combination of poor user interface, crypto sometimes results in undesirable tradeoffs (e.g. worse data deduplication for dropbox), and not enough perceived benefit.

What's stopping cryptocurrency's widespread adoption is what they call first-world problems.

1) Government that doesn't confiscate your wealth (more or less) 2) Dollar bills that don't go to zero 3) Banks that don't steal your money

Take away these and you'll see capital flight all over the place and some of it will end up in Bitcoin

Usability. It's hard to use and even harder to use well.

Sorry for the ambiguity, I meant Crypto currencies

I think the present culture of indulging in nearly unmitigated crypto-Utopianism is the more interesting concern. It's becoming difficult to argue against cryptocurrency in the tech industry without some form of rebuke enumerating the various potential applications (none of which are in dispute, generally) and/or incoherently equating cryptocurreny to the internet or other such developments (in this story, the future will render skeptics little more than 21st Century Luddites). For an industry so predicated on logic, it's kind of alarming to hear such blatantly shallow reasoning. The militant proselytization of cryptocurrencies often verges on absurd. We should be actively challenging and questioning our beliefs about something that has attracted so much attention and money.

All that said: cryptocurrencies might succeed. No one can outrightly deny the possibility. We should stick to arguing as to the likelihood or the extent of 'capture' it might achieve.

The forest for the trees that the more devoted crypto-Utopianists are missing is that cryptocurrencies, and perhaps the blockchain concept more generally, are at present an inferior or nearly inferior mechanism on almost all of the dimensions we should care about: speed, convenience, stability, cost. Put in short, a commercially-motivated centralized actor, backed and regulated by one or more government authorities, will always be able to perform as well or better on most of these dimensions than cryptocurrencies, no matter how many improvements are made to the system. We usually then end up asking if that system is problematic or should be challenged. In the first world, there aren't presently enough people of a subversive mindset to prefer cryptocurrencies to a centrally-regulated system solely on the basis of anonymity, complete transaction transparency, and decentralization (the principal advantages of cryptocurrencies). That could change, but it seems fairly unlikely. Importantly, I'm not taking a political stance here. I'm instead trying to account for human behavior.

Cryptocurriencies are nevertheless valid stores of value. People have relied upon all sorts of things throughout history to store value, because achieving the designation is as simple as getting some people to trust in a particular system. But the thing about stores of value is that they inevitably offer variable degrees of reliability and trustworthiness over sufficiently long time horizons. It would be foolish to argue, for instance, that the US dollar will remain the predominant global reserve currency in perpetuity. What we can argue with a higher degree of certainty is that the US dollar is unlikely to experience a catastrophic, abrupt decline in its trustworthiness. I would posit that the same cannot be said for cryptocurrencies and the primary reason for this is that some substantial proportion of their value is likely baked on purely speculative behavior (the volatility suggests as much). A secondary reason is, ironically, that there is no central authority to intervene in the event of a panic-induced selloff. And the real problem is that there will always be stores of value that are relatively more trustworthy, according to the public at large. The average person can see and feel gold. They understand that it's a store of value and history reaffirms their conviction. They don't have to comprehend very complicated technical and economic dynamics to believe in gold. Now you might argue that cryptocurrencies can remain stores of value without realizing broad adoption and I wouldn't contest that. But the risk exposure they present, relative to other available stores of value, seems at the very least problematic.