government people think in forms, I guess this was originally a paper form you had to submit signed via mail (not email). their logic is that they have to have something signed so they can hold you liable if something is wrong or even fraudulent. when you don't submit they won't know if you forgot or really didn't have any business. they could of course design the system a bit more user friendly but knowing government agencies that means it would involve some highly paid consultants working for several years with an even more hostile user interface