Oh bugger it, rules are made to be broken....
It's an interesting rant, I pretty much agree with the bit about owners cleaning up. I'm less interested in the control debate, I see far too many parallels in this kind of rant to drivers on other forums ranting about cyclists on roads, of course the irony is normally lost on most people. If I wasn't a cyclist, I don't think I'd support shared use paths, most cyclists are simply too inconsiderate to use them safely. what's that you say, you're not one of them, oh really. Well I apologise for tarring you with the same brush, I can't think how that happened.
And you're right, dogs don't have rights, owners do. I think under law, dogs are seen as a usual accompaniment and public land is just that, for use by the public and their usual accompaniments.
I refer you back to my earlier post about everyone rubbing along.