I wrote:

> What you appear to be suggesting is that for the sake of the 95%, the 5% should not be permitted to "fix" things to work as they want them to work. And that if we do customise then we'd be unable to understand that what we are running isn't the standard UI. Yes there will be some people who blindly customise "because they can" without understanding the consequences - but I don't think that's a large enough proportion to justify telling the 5% that they CANNOT use their own systems as they wish.

And I left out ...

And you are also ignoring in your problem statement that just because I may not have customised my UI does not mean that it bears much relationship to what someone else using that UI is seeing. From what I read, the Gnome team seem to be following Microsoft's lead in "changing stuff when they feel like it".
I recall reading an article many years ago, where the author was challenging the "we must use Windows because everyone else is and people know how to use it" mentality. I pointed out that Windows 95 is very different to Windows 3.1 (that dates it doesn't it !), and NT is different again, and CE is different again, and Mobile is different again. Bringing that up to date, XP is something of a culture shock from 98, 7 takes that to a whole new level, and with 8 ... well you might as well assume you know nothing (it's actually easier, IMO, to use if you don't already know how to use "Windows"). Then 8.1 changed it yet again, and 10 changed it yet again.
I see the same problems with the server versions - and (not regularly dealing with them) on more than one occasion I've had to ask a colleague how to log out of this completely different version of the UI !

Perhaps many of use are falling into the trap of liking what we are used to. One thing I can say about Windows (8 and later) from watching non-technical and non-experienced users is that it really isn't easier for people to use - especially with the many "non-visible until you do something to trigger it" features.