1. Existing payment systems expose your entire financial history to the service provider (e.g.: your bank, your credit card company etc.). I don't understand how people can complain about surveillance and data collection by tech companies, and then be perfectly fine with consumer finance companies doing the same thing.

2. What is legal is not what is moral. E.g., outlawing sex work, which results in SWers in even Western countries getting kicked off traditional payment systems, or having SW forums taken down (e.g. backpage). Having a decentralized and censorship-resistant infrastructure for these essential utilities is vital, and blockchains can be a key component of that infrastructure.

3. As a cryptographer, PKC and digital signatures have thoroughly failed to provide a decentralized and secure P2P communications infrastructure. (And no, Signal doesn't count: it's fantastic, but it's run by a benevolent operator.)

Honest question: What if coinbase is hacked, and the info connecting people's verified real-world identities to their wallet is revealed? Now everything is public - isn't that worse?

Yes, which is why cryptocurrencies enable self-custody, so you only need to trust yourself.

>> 1. Existing payment systems expose your entire financial history to the service provider (e.g.: your bank, your credit card company etc.). I don't understand how people can complain about surveillance and data collection by tech companies, and then be perfectly fine with consumer finance companies doing the same thing.

Generally people have choices in how they handle their finances: you can choose which financial institutions you use and how you want to pay most of the time. If you don't want to be tracked, you can get cash and pay with cash.

However, some of the tracking can be to your benefit. Most banks and credit card companies offer some degree of fraud protection / prevention and if you have a good credit history and want to take out a loan, they will happily give you the money. It requires a real-life trust relationship where the bank / finance company is a trusted business partner and not an untrustworthy predator.

If you find the relationship with your bank or credit card provider it not to your liking, you can choose a different bank or credit card provider that offers more favorable terms.

>> 2. What is legal is not what is moral. E.g., outlawing sex work, which results in SWers in even Western countries getting kicked off traditional payment systems, or having SW forums taken down (e.g. backpage). Having a decentralized and censorship-resistant infrastructure for these essential utilities is vital, and blockchains can be a key component of that infrastructure.

I disagree here. I personally do not think that sex work is moral or 'an essential utility'. If a payment provider does not want to offer payments for illegal or immoral products or services that is their choice. Some payment providers might still be willing to, but no one can really stop cash payments.

You do have a point here though, no one can stop blockchain-based payment systems and they have been instrumental in the recent increases in malware and ransomware.

>> 3. As a cryptographer, PKC and digital signatures have thoroughly failed to provide a decentralized and secure P2P communications infrastructure. (And no, Signal doesn't count: it's fantastic, but it's run by a benevolent operator.)

PKC and digital signatures don't provide infrastructure. They provide tools to be used at endpoints. You can use freely available cryptography tools such as OpenPGP (https://www.openpgp.org/software/) to generate your own keys and securely communicate with someone else over existing communication infrastructure.

> 1. People have out-of-band trust relationships in real life which reduce the likelihood of malice. Bitcoin-style anonymous identities undermine trust relationships and are not needed for legitimate (not illegal) transactions.

Bitcoin provides pseudononymous identities. Just like how someone can move to a new domain or amazon account after word gets out that they are selling deffective goods.

Trust only goes so far, even when dealing with people you should be able to trust. If this were not the case, then close-to-home scams would not exist. E.g. embezellment and other forms of stealing from people you work with face-to-face.

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>2. Real life legal systems encourage good behaviors. If you have a dispute with someone, you can sue them. Bitcoin and related systems lack these protections.

The legal system is complex, slow, and _EXPENSIVE_. A lot of bad behaviour also goes unpunished when the cost to rectify is greater than the amount stolen. Offering an alternative, low-cost and quick system, and accepting the downside of there being no "takebacks", who is to say this is a strictly negative thing?

There is also nothing stopping a service provider from stepping in and providing dispute resolution by way of mostly automated eskrow. If the transaction of goods for money happens without flaw, then the money is released automatically. If an issue occurs but the buyer and seller can resolve it amicably, that two is automated. In the unlikely case that one or both parties are malicious, the service provider reviews the case and releases funds as appropriate (e.g. checking that the parcel was actually posted, reviewing images of the good if it was damaged in transit, resolving as best able in case of scams).

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>3. Existing tools such as public-key cryptography and digital signatures can provide most of the functionality that applications need without the problems that blockchain-based systems have.

They can, but there are very few examples of such tools. This is hackernews, and this opinion is repeated ad nauseum, yet I don't see anyone actually going out and hacking something together.

Just like how it has been possible for financial houses to open up APIs to allow people to better manage, automate or make their money work exactly they want; it should come at no surprise when something comes along that actually allows this, no matter how much people cry that this was all possible and much more efficient without $NewTech, the people that have adopted said $NewTech aren't going to care too much.