Atomization pressures in gasoline engines with injectors is low... a max of about 50psi. Diesel can go as high as over 100,000 psi.

There are all kinds of reasons shy gasoline atomization can't be made as good for gasoline as for diesel. But the biggest ones are the taxation and the lower amounts of fuel used.

You get much better mileage if you stick a Kabota diesel of comparable size in a gasoline car.