Specifying some minimum property size should cover most cases, as well as specifying land uses that are or are not covered by the requirement for public access.
If you own a large parcel of land but are actively farming it, I think disallowing public access is reasonable. If you own hundreds of acres of wilderness, I think public access to traverse the wild areas of your property is perfectly reasonable, even light camping with reasonable restrictions. Specific issues can be prosecuted individually, instead of a blanket ban on all public access.
