I find it very hard to understand how an employer could not know what they want or need in a new employee. I understand that it happens, but I have no idea how someone decides "hey, we need a new person" and has no idea what they would like that person to do. Hiring is a hard enough problem without handicapping yourself out of the gate by not having and expressing a clear idea of what you're looking for.
How hard can it be to say "we're looking for someone who knows enough Java to follow our codebase without needing their hand held. We are also dabbling in Python so that will be a plus if you know it."? Why can't a req for an experienced engineer read "We need someone reliable and knowledgeable enough that they can do all the handholding our other developers need."? There must be some part of this that I'm missing, because actually writing a req seems too damned simple to be this FUBAR'ed.