Ad,
I'm a known sufferer of "hoof in mouth disease" so if I came across as seeming like I thought you might go "hacking [your] way through the national parks" I'm sorry. I really didn't think you might. I intended to be more illustrative and less accusatory.
Nor do I wish to suggest to you, Finn or anyone else that you should forgo emergency equipment because "it's too heavy, [and] you probably won't use it." My point is merely that one's emergency equipment ought to be chosen with an eye toward what kinds of emergencies one might reasonably expect to face. If you think there is a reasonable probability that you might find yourself in an emergency where you would need a khukuri and a smaller blade would simply not do the job, then by all means carry the khukuri. Of course, if you
expect to use the khukuri for non-emergency purposes, e.g., trail maintenance, then naturally you should carry it.
I can think of lots of situations where I would rather have a khukuri than a smaller blade, but few of them strike me as emergencies where I could not muddle through with the smaller blade. Obvious sorts of cases are like the medical emergency when you might have to chop and trim a couple of poles to form a stretcher or travois to evacuate a comrade. With a khukuri you can do the woodworking part of that in 1/4 or less the time that would be required using a 4-5" knife. OTOH, the woodworking part of making a stretcher or travois is probably less than 1/2 the total time (even with the lighter knife) so your total savings is a much smaller percentage of the task. If I'm worried about mountain lions, I'd imagine that a pistol (per person) would be at least as effective.
I certainly don't have any problem with rationalizing buying a khukuri. I may be more rational than some folks (or not

). I only have 8 (plus a couple of kagas katnes) at the moment.

I really don't want to discourage you from buying one. I find my khuks pretty useful around home.

If I were planning on living off the land for an indefinite time, I would definitely want a khukuri. OTOH, for a weekend backpacking trip in the desert, where there is probably not a lot that I'd need to chop in any case, I doubt that I'd want to carry a khukuri badly enough to spend much of the strength that I could otherwise be using to carry water. YMMV.
Paul