I'm on the side of the food trucks, but this is an easy question. It replaces the need to enforce food safety regulations, which is hard, with the ability to enforce simple bans on the trucks' existence/presence, which is easy.
If you know food trucks are doing terrible things, but you can't prove they're doing anything wrong, you can solve your problem by dropping the evidence requirement.
If you know food trucks are doing terrible things, but you can't prove they're doing anything wrong, you can solve your problem by dropping the evidence requirement.