Oh yeah. Part of the pain is that I used to work for a library (though not as a librarian) and am therefore familiar with the well-intentioned donation concept.
Yeah. There are a ton of things where "surely someone somewhere would want this and might even pay a nominal sum for it" is probably true. But spending a couple days setting up a yard sale, arranging things on Craigslist (much less individually packaging up and selling items online), etc. just isn't worth it.