Just because the state or local community can ban something doesn't mean they should. One can be a supporter of states rights and against the state imposing harsh restrictions on individual liberty, even if the states have the right to do it. This law uses the same logic as the soda size ban in New York City that so many complained about. If people think that GM food isn't unhealthy and want to grow/eat it they have the right to do so just like you have to right to eat organic food. This law will inhibit the right of individuals to utilize their private property in a way that they see fit.
Big government isn't the answer. If you want to get rid of GM food then educate people so they can make the decision of what they will eat and grow. You have no right to use violence and the force of government to impose your beliefs on what is healthy and what isn't. Replace the word GMO with saturated fat, sugar, cigarettes, marijuana, etc. and the logic of the argument calling for banning GM food is no different than the logic used by big government progressives that champion these local infringements on our liberty.