It seems to me that land held in the public trust obliges the holder, usually some government, to stand in the place of the landowner and exercise the rights appertaining thereto. This includes regulating who and what may be on the land and the uses to which it may be put. And there is the additional burden upon the trust-holder that the trust must be managed for the common good of the public as a whole, not privileging any one member of that public above any other nor permitting to any one member use of the public land without ensuring that such use does not conduce to the detriment of the public as a whole. Too, the use of public land without compensation to the public, usually through the trust-holder, seems to me to be theft of some sort; if benefit is derived from the public, benefit should be returned to the public.
Ensuring these things does not seem to me to be overreach by the trust-holder. It seems instead to be just and appropriate--as it would on the private, local scale. If I hire a group to manage my property (assuming in some distant future I have any, or in some alternate world where I wear red instead of blue and therefore invested wisely), I want that group to be sure that my property is used in a way that benefits me, and if another person wishes to use that property, I expect to be compensated for the use of what is mine. Returning to the broader, public scale, if land is held in public trust, I have a stake in that land, as do my wife, my daughter, and the many members of my family and of many other people's families. We own it. We are therefore entitled to compensation from those who seek to use it to their own direct benefit, and we are entitled to protection from those who will seek to steal from us by refusing us such compensation.
It seems to me also that it is disingenuous to privilege things selectively. For instance, if I draft a document consisting of several articles but have to later impose some amendments to that document, it will not make sense for me to neglect the articles in favor of the amendments except only where the amendments directly address the articles. If the amendment speaks of something entirely different, then it seems to me that the article remains in force. If the article prescribes a penalty for something that acting in a way supposedly implied by the amendment causes, it seems to me that the penalty must still be applied. And if I have hired people to ensure that the document is enforced, I want to see that enforcement occur.
I expect to benefit from certain systems, and I do benefit from many of those systems. I am therefore obliged to support those systems. Such support can certainly include changes to them to make them more just and equitable, and I do work to those ends. But I do not set aside the systems in their entireties, and I do not selectively reject them. I cannot and still demand the benefits of them--not with a clear conscience. And I already have enough guilt to carry without adding to it.