Admins are currently given broad leeway to customize the user experience for all users, including addition of site-wide JS, CSS, etc. These are important capabilities of the wiki that have been used for many clearly beneficial purposes. In the long run, we will want to apply a code review process to these changes as with any other deployed code, but for now the system works as it is and we have no intent to remove this capability.
Sorry, I strongly disagree that the current system works. Every so often we discover that a wiki has been loading external resources in site-wide JS for months. Local sysops might have no idea on what they're doing, and just copy and paste what someone told them to do. Edits like [1] make that terribly obvious.
I filed bug 69445[2] as a tracking bug to implement a sane code review process for these pages. I don't imagine it will happen anytime soon, but now seems like a good time to start discussion about it.
I'm fine with having some sort of code review system, so long as it is implemented in such a way that there are volunteers with +2 for it.
I'm not sure implementing this user right though was the best way to go about beginning that implementation, at least with the sort of charged atmosphere that currently exists within the Wikimedia editor communities.
Perhaps the change could be reverted and we could spend some time on this list discussing how such a code review system would work? Give some time for the editors to calm down and all of us to calm down. (A quick look at Meta shows a lot of hate.) I think if this is implemented slowly with lots of notice it might have a better chance of succeeding. I think Erik's commit is likely poisoned at this point and any work that stems from it is unlikely to be accepted by the wider community.
I like the discussion that is going on in #69445, thank you for filing that Legoktm.
If nothing else, this whole debacle brought this issue back to the center of discussion, somewhere where it needs to be.
Thank you, Derric Atzrott