I don't know. Many mental illnesses take on different and varying forms.
I mentioned somewhere in the thread that my mother stored a lot of stuff, and she too was a child of the Great Depression. Seems to me that just about everyone I know who lived at that time tends to stockpile things. The Depression so traumatized many of them that they feel they have to keep a lot of things around, "just in case."
My father used to keep a lot of tools and other "guy things", but I think it had more to do with the fact that he often let things get cluttered. He would buy, say, a hammer...then the hammer would be buried under some stuff so that he couldn't find it, so he'd go out and buy another hammer. After he died, my brother undertook the task of cleaning out Dad's workshop, and he found so many duplicates of things. Most of the basic tools I have in my own home -- hammers, pliers, wrenches, screwdrivers, etc. -- came from Dad's duplicative collection.
My brother and I both have times when we live in clutter. Is it an inherited trait or something learned? I tend to think it's the latter. However, none of us -- my parents, brother or I -- never got to the point where our homes became unliveable. I think that's where the line would be crossed, and professional intervention might be necessary.
My mom has lots of duplicates, too. The one that got me was a generator, and several professional garment steamers. I know someone who will buy new clothes from a catalog to avoid doing laundry!
But in my case I think it's because I'm an only child and was taught never to waste anything. Of, I do some things that are wasteful, but I try to avoid that.