One could very easily argue that the USER ought to be empowered to take control of the UI. I'll use MS Excel as an example of a tool that I've used with regular

One could very easily argue that the USER ought to be empowered to take control of the UI. I'll use MS Excel as an example of a tool that I've used with regularity since it came to market. MS thought they knew better and utterly destroyed the UI with the introduction of Office 2007. As anyone who was a power user prior to that version and you are very likely to get a nearly unanimous thumbs-down on the changes. The ribbon interface, as well as other choices MS made, took a power user and made him/her feel like a total idiot. Could you learn it? Sure. Could you find the commands you needed? Of course. And, for a period of days and weeks your productivity went down to nearly zero. Here is a case of a company thinking it knew better and pushing forward changes that actually destroyed productivity in a massive way. That sort of thing led me to thinking that users ought to be empowered to completely customize their UI. Keep the mainstream on the new shiny thing, but enable a setting that allows me to use a text editor to completely redo all of your choices. Create a marketplace for the sharing of these config files under source control too. A mechanical engineer will have different needs than an executive assistant, not in complexity but rather in context and workflow.