It's also a very natural way to speak for anyone who gambles, or deals with financial markets. And the lack of precision makes it very clear it's just based on thinking, not some sophisticated mathematical model.

> But research has shown that people translate vague phrases like "a decent chance" into probabilities in inconsistent ways.

That is not a bad thing. It captures uncertainty, unlike the fake number.

> For an ML researcher who is already used to dealing in next-token probabilities that aren't rigorously determined, just stating a probability estimate directly is very natural.

Exactly, it is a rhetorical device to persuade a technically-inclined audience. It works because it implies that a quantitative model exists. I want a clear, incisive set of mathematical arguments. Otherwise, I’m ignoring predictions as the ramblings of arrogant idiot rich kids.