"the argument seems to be that EH and other professional bodies know best and no-one else (i.e amateurs) needs to get involved and indeed should stay at a safe distance away where they can do no damage to anything."
No, that's a misinterpretation.
Coming several hundred miles to a World Heritage Site, saying the local archaeologists are illiterate, and then climbing up a monument without having an advance word with the local statutory guardians strikes me as wrong, that's all. It didn't need an identikit to know it wasn't Tompian. I admire Tompian, his modesty and behaviour. He's a good example to the public.