I think crop Rotation was something that developed from a need to stop certain pests etc get a strangle hold in the soil.eg Tomatoes,and other crops that suffer from too many plantings in same beds.
My self I think it may of come from the organic gardners who noticed these anmoloies after care full study of the gardening practises.this has changed slightly with the intro of nitrogen plants and soil conditioner plants while they rest for a period.
With the advent of permaculture plus others this may of changed due to different ways of soil treatment,resting and management,also the absolutly amazing varietys of vegatables these days compared with yester year....
With Permaculturists leaving plants to go to sead,this has caused seads to blow any/every where,so as to grow in allmost anywhere they like/able to...
the concept of never having bare ground as a permie has altered this too.bare ground is bad ground/weeds grow where the soil is bare,so i suppose crops wwere planted rather then a heap of weeds taking over and leaving soil nutrientless because of it..
I think it all boils down to experience,skill forsight and knowledge after that..permies dont like empty spaces other gardener types dont mind.
Its all a matter of choice after all.with permie pratices,all kinds of nutrients can be added all year around,any time,in a modern vegie growing area its not allways practacle to,do as is in a back garden situation...
The skills we get taught are for commercial productions ratgher then just
a family.both have their merits as well as their downsides.A permies garden Once established should be self working ,,,As apposed to a conventional garden requiring a continual presance and continual monitoring maintanence...
Permaculture is Based on the Forrest Principle.Not the conventional meens
Wellcome Mike from New Zealand hope u visit often
3 acre town site block
Available to teach various Permie Subjects
Allmost 22years experience
"Permaculture. Just Do It"