I guess my problem with plastic is the same one Fletcher talks about in connection with his Visqueen tarps: they are disposable, and intended to have a short life span; as a result, they tend to get discarded and left in the backcountry for someone else to haul out (or, worse, for something else to eat.)

On another thread, there's a few postings about using trash bags as pack liners. Same thing: it will eventually hole out. It raises the fundamental question of whether you should go cheap, knowing that you'll run through a bunch of them, or buy the nylon pack liner a few companies sell, which will last as long as the pack itself (and may, in the long run, be cheaper.)

I have no problems with the folks who use these bags and conscientiously pack them out, every time. It's the unnamed folks whose litter I keep packing out that bug the crap out of me.