Yeah, I never understood the need for this gizmo - and I usally love my notions! A friend who has everything sold hers at our guild's "garage sale" night.
When I wind bobbins, I do several at a time. It's a long time before I need them again. When I'm getting to the last couple of them, at the next convenient time (NOT when I'm in the middle of a long seam, lol), I do several more.