Why or why not by the end of 2020? Why not by the end of 2021 or 2025 or 2050?
They're both mute on this point.
Yeah, I get that. But why or why not should it happen in 4 years? Why not 6 or 8 or 3?
These numbers seem just pulled out of a hat, and their arguments would make as much or as little sense with a different date.
Hence Pinker's remark about 15 years of hindsight, and the fact that some of the comments below the line were posted 19 years ago.
With this in mind, I'd suggest that 2020 was picked as an arbitrary "sci-fi future" date rather than for an arbitrary term of 4 years. Still arbitrary yes, but more understandable in my view.
Let's say you're trying to argue why we'll run out of helium in, say, 10 years.
You could say: we have 10X quantity of helium, we use 1X per year, therefore we'll run out in 10 years.
Or you could say: we use a lot of helium. We're bound to run out of helium sometime, therefore we'll run out in 10 years.
The arguments presented in this bet are of the second sort. They do not say anything about why what they're betting on should happen in 10 years or in any other timeframe.
Sure, the bet is for the end of 2020, but in order to be persuasive you actually have to make an argument for why what you predict does or does not happen in that timeframe.
No such arguments were even attempted here. That's what's so frustrating.
Simply put, they guessed; it's a gut feeling.
And whether an argument is persuasive depends on what the argument is and on the people evaluating it.
Arguments with using hard data and actual reasons for picking a certain time frame are not automatically persuasive.
Take a look at the Peak Oil arguments that were made. They had pretty hard numbers and reasons for their predictions, but plenty of people were not persuaded.
Another example is Ray Kurzweil's predictions about the singularity, which also had their reasons, statistics, etc, but plenty of people disputed them and made counterarguments.
But least you could tell why they believed their predictions would happen within that timeframe.
No such evaluation is possible with the "bioerror" predictions, however, since they didn't make arguments for why it should happen by the end of 2020, but instead just expressed their "gut feeling", as you point out.
That's absolutely worthless.
A gut feeling is absolutely an argument. It may not be a well-reasoned, evidence-supported, or persuasive argument but it absolutely 100% is an argument.