All these environmental ethics debates always eventually get a "what i am doing isn't as bad x , y , and z so i feel justified in my behaviour". It follows that "my nalpalm strike on a small village is morally defensible because others blanket bombed entire cities just up the road".
A "f---ing great national park" like the grampians is supposed to be preserved, that is the point. Obviously this is fatally flawed because people visit it and impact it in various ways. If you care about what someone else is doing to it do something about it, otherwise take responsibility for your own actions. If you can justify to yourself that leaving a plastic tarp discreetly in the bush is an impact that is worth you not having to carry it in and out then fine, you have just taken responsibilty for your actions. The same applies to bolting and walking off track and cleaning routes and just being there.
But this idea that "they did it first" or "they were more badder than me" shits me to tears. (deep breath). Sorry alrob you may have just copped the brunt of something that has been simmering for some time.