As I see it, a yes vote will allow the park system to keep the monies that it generates. As it is now the money the parks generate are being given to the state's general fund and therefore used for what ever the legislature wants. Some trickles back to the parks and the rest goes to prisons, agriculture, roads, salaries, etc. There is a provision to allow for the parks to employ commercial businesses to do business inside the parks (concessions) when and where fesible, not to operate the park itself.
By voting yes, the park system will allow the parks to grow and enhance their properties which should bring in more visitors to the parks and thereby bring in more monies to the surrounding communities. That means more tax dollars for local governments.