[Haskell-cafe] Why isn't hsc2hs functionality provided by ghc?

[silly8888]

I was wondering today, why hasn't hsc2hs been merged with ghc so that
it would be possible to add a

{-# LANGUAGE ForeignFunctionInterface #-}

at the top of a source file and then load it with ghci or compile it,
without the intermediate step of calling hsc2hs? This would be exactly
like the CPP extension. I don't have to call cpp manually. All I have
to do is to add {-# LANGUAGE CPP #-} and then ghc will take care of
the rest. This would also mean that there would be no need to have a
separate file extension. Surely I must not be the first person to have
that thought, so there must be a good reason why this hasn't happen
yet, but what is it?