I am one of those people who feel a duty to "save" things, not people so much ("saving" people is impossible) but objects. I have a huge collection of vintage clothes, most of which I would never wear. I feel the need to keep them, to make sure they don't end up... gone forever. I do want to get rid of my vintage clothes but only to the right place and the right person, to someone who can be trusted. This sort of mentality is common for people who collect anything.
Currently, an opposite mentality prevails, one of "letting go", "de-cluttering", "simplifying" and the spiritualization of getting rid of things you "don't need". Not to say that hording is "healthy" (the spiritulization of health is another annoying trend), but there are differences between hoarding and collecting. I've heard someone say that hoarding is when collecting gets out of control. The next logical questions are about where that line is. To someone who doesn't collect that line is between how many of something you "need" and "don't need". To some one who does collect it's different, there is no "you need" it's more "you + future generations desire". Therefore, drawing lines between needing and not needing is even more pointless (who needs paintings, couture or old books?).
The reason I bother to write about this is because almost all of what has been preserved from the past has been preserved only because people have specifically worked to preserve it: collectors. Practically, the whole past would be lost without them. For example the bed above belonged to a pope, it is exactly the sort of thing no one needs. Yet without it (or presumably anything else since in this model almost nothing is preserved) we would have no idea what kind of bed the pope slept on. While seemingly a trivial detail, if we didn't know it, we might believe something totally untrue about the past. We already do have so many misconceptions, but the fewer facts we have the more we have to rely on our biases. Objects are facts. That is their appeal.
As for "real" hoarders, I'm not going to judge those people. I'll leave that to TLC.