I'm aghast that anyone, never mind a whole lot of people, would throw away a perfectly good tube just because it had an easily patchable (and patched) leak. Honestly, the patched tube is as good as new. It's just gratuitously wasteful to toss them. Eventually tubes will leak at the valve stem -- only then do they get repurposed for non-air-holding tasks (although I admit I don't have a lot of such uses so usually put them in the trash....but never tossed on the side of the road, right?)