Well the main problem is that population growth means that the traditional farming productivity - while sustainable for millenia - just isn't enough to feed the whole population of Indonesia and Bali in particular. Bali went from 1.5 million in 1945 (independence) to 2.9 million in 1989. The traditional approach is opening up new land but of course you can see how this is unsustainable.

So unfortunately the switch from biannual harvests to triannual harvests using factory-borne fertilizers and deep water usage was necessary.

(I was taught this in a fertilizer factory visit near Surabaya a few years back, so my information might be highly biased. But demographics data is there and ... It is what it is.)