No argument here - if you walk into any hiring situation without some knowledge of fair market value, you are in a bad spot. I think candidates don't prepare for the question as well as they should and try to improvise on the spot, and many are not good at the improv. Having a number that is well-researched is quite useful, and being able to negotiate on your feet as necessary once numbers are discussed is important. Email is made much of that easier, as numbers are often shared in that manner instead of in live conversation.
Yeah, but I assure you that most of your entry level job seekers have no idea and either ask too low or some wildly inflated number (my friend over at blah blah was offered $120k...). It's more about being able to justify your expectations than having an accurate number which is why softer targets like ranges or previous salaries are usually easier.
Entry-level tend to fall into two categories in my experience. One are the "...but I'm willing to negotiate" types that end up getting 10K less than their likely value, and the others are the ones who ask for some stupid number like you mention and end up blowing a handful of solid opportunities before eventually learning how the game is played. For both, it's part of the learning process.
I agree that ranges are not a bad idea, but having a target number to quote (even if it is a few K above what you are willing to take) and a basement number (will not accept below) is a good idea.
