There's an old Dilbert comic that said something like "We want to hire engineers who are really good at what they do, but cannot compare two salary numbers and identify which one is larger"
The problem isn't that; it's all the information you don't have such as "how much are they theoretically willing to pay me," "who else would hire me," "how hard can I push before they just pull the offer," "do they have other candidates they liked," and so on. On top of that, lots of people in this career are not smooth talkers and they're risk-averse.
