Interesting, thanks for the link. My comment however was in response to the comparison cave/hut, not caveman lifestyle in general. But I get what you're saying. Maybe we're just fundamentally unable to live sustainably, by design so to speak.
/grandiose We are genetically programmed to live for a few decades, reproduce, and care for our kin (both blood and tribe) in a world which was limitless (relative to us as individuals.) I deeply fear this is the sad answer to the Fermi paradox. Now, our survival depends on outsmarting our short-sighted genes.