it's a captain's responsibility!
we should MAKE the first officers handfly--within reason. and take away the flight directors and closer in (abeam or base) take away their map.
i watch the early part of the flight and see if there is the basic potential-- and within the company rules, (not into LON TMA, wx) i will often reach up and turn off the auto pilot and tell the first officer that is has failed.
after their initial shock, they always thank me when it is finished. i know that sense of actually having done something.
and it is a handfull even in good weather if you don't do it often.
i remember the 737-500 estonia that lost all his air data not long ago and was told they have the same air data boxes that our -800's use.
so we must take the initiative and give them the opportunity/challenge.
if that makes me a rebel and a dinosaur, so be it.