Sure, there are some things that obviously have value... the oft-cited example being "a cure for cancer". And maybe some people just have a well developed intuition for what will or won't be in demand.
And, of course, the old saw about "If Henry Ford had asked his customers what they want, they'd have said 'a faster horse'" has some merit to it. There's a place for being a visionary, and if you're really building something visionary, sometimes you have to build it first and then show it to people for them to "get" it.
That said, I argue that for most entrepreneurs, you're not Steve Jobs or Henry Ford (or whoever), you don't have any special intuition about what will or won't be in demand, and market validation is a useful tool in the incipient stages of your project.
Also, the point of making attempts to validate a market isn't just about determining "does anybody want this"? It's about determining if enough people want it, if they will pay enough to make it profitable, factoring in the overhead of selling to them, and ascertaining how to best market and sell to that market.