My understanding of the PSK approach is that it's there for when you lose the kit that you would normally use. The tobacco tin idea seems to have been started by the SAS (although I could well be wrong) for those situations when they would have to leave their kit behind in a hurry. In a hiking situation I could imagine a river crossing going wrong and your rucsac getting swept downstream. Maybe in North America a bear steals it, I don't know. So the little tin is a backup to your day to day survival gear, not something you would be dipping into whenever it takes your fancy. Of course in the UK most of the comercial survival kits (BCB, Penrith) are mainly irrelevant for most hillwalkers. What we would need is a whistle, a surival bag and a mobile phone. And some Kendal mint cake of course. Fishing line etc would be of no use on Pen-y-fan or Ben Nevis