I will start my post by saying I relate to and validate your feeling.
However, your analogies are weak sauce and your argument has more holes than cheese from Sweden. You, or your pappy or his pappy did not build "your" stream but "I" built my pool your talking about soiling yourself in. Additionally this discussion is about a change of law, by the same government that ran the Indians off of their land, not people deciding one day that its OK to wade in your creek and doing it, so by your reasoning you should support the law after it is changed by the same government right???
Also, one would have to think that if all streams were yo become accessible to the public that they would also have the same applicable liability laws as the navigable streams now do.
Again, I will say that I would be against the law were I in your shoes, based purely on feeling but your argument to back your feelings is weightless.