I think your response raises an issue of perspective. Are we focusing on fingerprint technology from a user's point of view - or are we considering its implications over many years?
This reminds me of certain U.S. Supreme Court decisions. As someone who's interested in constitutional law, I often find myself defending things that seem trivial and nitpicky. Why does it matter if the police enter one drug dealer's home without a proper warrant? Who cares if we restrict someone's speech, considering that the person was, say, a racist whose ideas were ignorant and offensive?
Of course, the content in this analogy is very different. I'm not comparing fingerprint scanners to crimes. But the logic is very similar: when judging law and technology, respectively, it's important to consider how seemingly small decisions serve as a precedents for bigger trends.
If fingerprint scanners become a common replacement for passwords, and the author's argument is correct, the scanners may dramatically change our security and expectations of privacy.
Consider the thorny issues of courts forcing people to turn over passwords to decrypt phones to implicate themselves. Typically, it's a constitution tarpit as you should not be forced to implicate yourself.
However, your fingerprint is a username in that case because it is all over the place. The police already have it. Don't be fooled, there are certainly kits being sold to law enforcement to dupe TouchID. You're data is less protected from those that you'd probably prefer not have easy access to it now.
This is a disadvantage only when you are on trial. That's a pretty extreme contingency, and I think most people who aren't internet privacy advocates wouldn't be particularly worried about their phones, of all things, after they've been arrested and indicted.
Outside the HN bubble, this is an acceptable tradeoff. People who are concerned can continue to use passwords.
Outside technological bubbles, people don't understand the implications of technology in regards to security and privacy. You're speaking about "tradeoffs" however people don't understand the tradeoff and will think fingerprinting is secure, because look, Apple is doing it.
Therefore it is up to us to make the right choices. That we aren't doing it, choosing instead to defend flawed technological improvements and the companies doing it, is very regrettable.
> This is a disadvantage only when you are on trial. That's a pretty extreme contingency
No dude, that's not the only thing that can happen and it's in no way extreme. Many people do go on trial for trivial things (because shit, in the US at least, suing people is a way of life) and your laptop or phone contains your most secret conversations and desires, being the ultimate incrimination tool, a digital fingerprint of your own mind.
And you don't have to be on any trial. You don't even have to be a suspect in an investigation. It can happen and has happened for laptops or phones to be seized for inspection during routine filters, like by the airport security.
Also, in the US you may live under the rule of the law. What about countries where oligarchies rule, countries where corruption is the norm? What about countries like Rusia, China, India or Brazil?
Just today I read about a story about this traffic cop from my own country that had the bad inspiration of doing his job by fining his own boss for ignoring a red light and exceeding the speed limits. He was later accused of all sort of bullshit and had to fight it in a court of law for 2 years before he was exonerated.
And technology evolves and our devices are gradually becoming our stored memory. What do you think these corrupt officials or organized crime syndicates could do with your own mind, 10 years from now? A lot dude ;-)
It's easy to say that now while you're not on trial. What happens if the day comes where you are on trial, for something you may or may not be guilty of and what you have on your phone could potentially incriminate you, corroborating false accusations? We see it all the time, information is translated out of context and used in ways it was never supposed to be interpreted. It happens all over the media, it happens in smear campaigns in politics, it happens any time someone wants to get ahead of you on the promotional ladder. It's too late to come back after the fact and say "Well shit, I guess I should have considered the implications of that technology being used against me when I considered it just as a convenience." Sure, it's convenient. I get that, we all do. But if you don't consider the price of that convenience up front, you can't come back and complain that it was used against you afterwards.
Also, configurable after a few hours it can ask the password anyway. A trial and being compelled to place your finger on the phone goes way beyond that. Or if they're going to beat you over the head with a metal pile regardless to unlock then the difference between a passcode or your fingerprint becomes meaningless.