I agree with you that the article is obviously pretty biased. I do wonder if the activity would not ironically be better served by allowing free press access. For example, I feel like I understand and support your points. I doubt there is a dangerous cabal of 'politically powerful ranchers' (also known as land owning citizens with rights to keeping destructive grazing animals off of their land), I doubt that there is a secret and nefarious plot afoot, and I don't really trust that this is that big of an issue for me personally. However, it is a big issue for me when the government decides what I am, and am not allowed to see. This isn't a national security issue. It's just politically expedient for the NPS to not have to deal with reporters stirring up trouble over buffalo slaughter. But lots of animals are slaughtered every day, and I doubt this would have ever been a news story I'd see if there wasn't the veil of secrecy.

But really the most important reason to make something public is so that if people who are not like me decide that this is an unacceptable practice, then they can voice that in a supported public argument and petition for a change. When issues are occluded you can't do that. For all I know, the only reporter trying to see this cull is the NYT author of the editorial. Regardless, the NPS can't be changed to reflect the peoples' desires without access to information and the issues. There are 4.2 million federal workers in the US. You can vote for 4. So at least you should have access to information which allows you to petition for change and create pressure with those 4.