The UN has a lot of problems beyond just its bureaucracy. I'm suspicious of it's ability to solve the problems it claims it exists to solve even if its bureaucracy was extremely efficient. It seems I read UN scandals on a monthly basis, to recall a few from the past few months:
Did you read the linked post? The abuse by its peacekeepers is what he cites as his main recent issue with the organization, and he indicates it was foreseeable and directly caused by the cynical and bureaucratic incentives in the UN.
I have a feeling the parent commenter knows the rule, but didn't care to follow it. Your comment seems like someone who walks up to every smoker they see and says "Did you know smoking causes cancer?"
Sexual abuse by it's peacekeepers (http://www.washingtonpost.com/sf/world/2016/02/27/peacekeepe...). "Child sexual abuse by UN peacekeepers" even has its own wiki page (https://en.wikipedia.org/wiki/Child_sexual_abuse_by_UN_peace...)
Bribes are abound, even a story earlier today (http://www.seattletimes.com/business/humanitarian-worker-cha..., http://nypost.com/2015/10/06/former-general-assembly-preside...).
Saudi Arabia is on the human rights council (http://www.thedailybeast.com/articles/2015/09/22/why-is-saud...). Not exactly a "scandal" but in the same vein.
It's ever-increasingly hard to take the organization seriously.