User blog comment:Rupert Giles/Global Navigation Update/@comment-452-20141202163302/@comment-452-20141203140227

Because that's standard procedure for A/B testing. It's not supposed to provide "user feedback", it provides "user performance feedback", because they're monitoring behaviour.

I suggest you read up on A/B testing if you want to know more about it.

It will not be an option for wiki admins, or an explicit option for users: but users can clear their cookies in an attempt to be assigned to a different group.

(In this case it's A/B/C/D testing, but close enough.)