HGTV and Oprah do a lot of "overaccumulation" stories. The worst cases of hoarding usually involve a psychological trauma or syndrome that requires significant counseling to overcome. It can also be an effect of aging-- when my grandfather went into dementia, no paper (other than toilet paper) left his two-bedroom apartment for over four years. Save a week's worth of junk mail & newspapers and then multiply by about 200.I don't know if this qualifies as frugal or just crazy.
Of course, occasionally something in one of the jars has come in handy, which just reinforces the "you never know when you might need one of these" attitude.
I gave up letting it bother me.
But you've also described the business models of "Antiques Roadshow" and "Restoration Hardware"...