I wouldn't include a knife in a PSK in the first place.
Really? Interesting...
Using that logic, you wouldn't have a firestarting method either, as you should be carrying one seperately anyway, and if you lose your PSK you still have it <img src="/images/graemlins/wink.gif" alt="" />
I carry my PSK to suppliment my EDC, but I still want it to be useful if I find myself with nothing else.