“But it seems to say that when times are bad, it isn’t appropriate to burden the family and the kehila with more mouths to feed.”
Your entire argument is debunked! You should have taken time to read Rashi!
Rashi in Taanis says the reason is that one should have a part in the pain of the famine and since marital relations are pleasurable one should refrain from relations while others are suffering.
Anyways, times of famine mean GLOBAL FAMINE, ala Ethiopia. It has nothing to do with welfare, food stamps, or fiscal cliff.