Well I won't argue that you were incorrect. I do have hoarder tendencies and I "manage" that by keeping it only digital. That being said, I think my point still stands because despite my more ridiculous examples this does still happen.

Lost classic TV show episodes that were thought lost to time are found again because of hoarders. Historical data on towns are kept by the person who has never thrown out a newspaper. Hoarding is bad, but it does prove to be useful on rare occasions. The fine line is saving potential chunks of history vs a stack of pizza boxes because they may have a use one day as storage.

You may take a hard no on the matter because of what you have dealt with what your mother is going through, but I argue there is some specific things worth saving.