Probably because the moderators felt there was too much information which could be used by amateur evil-doers, figuring out that big disasters could result from seemingly trivial actions. We have a lot of said amateur evil-doers among us these days.
I was also curious about their process. I had some long-ago experience volunteering at a 1:1 RR museum, where in my youth I was one of the strong backs/weak minds helping to re-rail equipment. Probably twice each weekend I was there, come to think of it.
