He certainly was the father of the 60 pound pack - but that's when packs weighed 5 pounds, tents weighed 8, and pots were stainless steel. In his later books, the 60 pound pack became 30 or 40 (he spoke of the "evolution" of gear) - and he cut his kitchen back from 2 pots to 1, and so forth.

However, he did take a lot of "what might come in handy," including writing materials and spare clothing. I'm not entirely sure, though, given some of the conditions he describes for his trips, where "might come in handy" stopped and "it's not unreasonable to expect to get snowed in for a couple of days in the mountains" started. (Your concept of "mission hardware"?)

But I think, yes, my philosophy is "take what might be required" and "don't worry about what might be handy." I've also found that the less I take, the freer my mind to take in the country I'm passing through and to just let my thoughts flow. I actually end up feeling "footloose" with the light pack I carry now.