If the government shouldn't regulate for human powered activity, then they should perhaps not provide the access or amenities for such activities.
There are many reasons that the state or federal gov't provides us with hiking trails and access points for water sports.
If folks had put their money where thier mouth was and donated money to groups that manage and maintain, then a fee like this would not be necessary.
How many times have you gone hiking up a mountain or on a trail or paddling down a river or stream and not given a second thought as to how you are able to do that, my guess is most of the time. Those trails and access points didn't just show up one day.
Heck, most people that are hiking on the mountains around here don't even know the proper trail etiquette for passing hikers in the opposite direction; do you? Very rarely do I observed that on any of the more accessible trails and you can tell the folks that don't know from a bend or two down the trail.
Personally, I would like to see more camping along our rivers in this state. Maine has 1000's of open camp sites along their rivers that are really well kept and make for great weeks on river. Not all of these are managed by private groups, more often, it is the state that provides and maintains these sites.
NH does not have any money for things like this and I am not thinking that this fee will provide for that, but it would be nice if the folks that are behind the writing of this bill, had these types of projects in mind.