It makes sense for it to be the same as solar power: just because most of energy generation is done in big facilities and even some kinds of solar generation (such as solar concentrators) can only be done in large facilities, doesn't make having some solar panels providing part of one's needs (or even all of one's needs for some of the time) less cost effective in Economic terms or a good thing in Ecologic terms.

So it makes sense to grow some of one's food, but maybe not go as far as raise one's own beef or even aim for food self sufficiency, both for personal financial reasons and health reasons. That it's also good in Ecological terms (can lower the use of things like pesticides and definitelly reduces transportation needs) is just icing on the cake.