I think some of these laws are in place 'just in case'. For example, our state parks prohibit any use of alcohol. A quick peek into the recycling bin at the end of the loop reveals a truckload of beer and wine bottles and cans. If some nutcase was terrorizing a neighboring camper by throwing or brandishing a big 'zombie killer' knife, it's nice that a LEO can put a stop to the behavior.
I don't think they are after the people who are splitting wood for the family campfire.