Is there any document describing why there is no ghc --strict flag making all code strict by default? Wouldn't such a '--strict' flag turn Haskell/GHC into a better C/gcc compiler?

I agree that a strict flag would turn Haskell into C--but that's a perversion of Haskell. Almost all Haskell code I write depends critically on laziness. Sure, there are little bits here and there that would run faster if I carefully decorated them with strict flags. But the genius of Haskell is architectural clarity, achieved in no small part by relegating nasty issues of sequencing to the implementation. If you even have to think once about what needs to be strict or non-strict, then non-strict is the only viable default. I can't imagine writing any interesting Haskell code that will successfully run all strict. Doug McIlroy