I haven't done a study or anything but after living in Florida for 5 years (coming from New York) I have to say that the motivation seems to come from a serious lack of other revenue sources for the state. There is no state income tax and so fee revenue is huge for the state and local municipalities. A few years ago, in central Florida, voters voted to decrease property taxes. When the measure went through revenues plunged. In response all fees at the DMV were literally doubled and a lot of public employees lost their jobs. The way Florida handles paying for itself makes no sense to me.