I presume that the market for coconut oil is far smaller than for jet fuel, so this solution can't scale without wreaking havoc on the environment. These sort of clever uses for exisiting byproducts only work when the market for the main product is much bigger than for the byproduct (e.g. down is a byproduct of duck/goose meat, leather is a byproduct of beef).
The existing solution is actively wreaking havoc on the environment. I don't know the specifics of this crop but generally agricultural products absorb a substantial amount of carbon when growing, so releasing some of that carbon by later burning has the potential to be close to carbon-neutral. Whilst petroleum fuels are 100% carbon negative.