I guess it's not so much top-down vs bottom-up per se - it's just that some people stop after the top level. Yes, that's not possible if you start from the bott

I guess it's not so much top-down vs bottom-up per se - it's just that some people stop after the top level. Yes, that's not possible if you start from the bottom, but then those people most likely would have gotten frustrated at the bottom anyway... On the other hand, I guess someone reading HN is rather likely of the kind that likes to open the lid and find out how things work.