Swapping hardware buttons for touchscreen controls has been a huge success for Apple for over a decade, with the iPhone, iPod Touch, iPad, even the Apple Watch. The Touchbar is just another step down that path.
It's arguable whether a fixed set of hardware "F" buttons are more usable, or well-labeled touchscreen buttons. Again, a decade of evidence suggests that software-defined touchscreen buttons are more usable. An iPad is much easier to use than a Mac. You can hand an iPad to a 5-year-old and they get it right away.
> They have gone over to Microsoft's philosophy, which was that UIs should be like an iceberg, with a deep well of hidden functionality for advanced users to discover, and then a separate "normal people" UI layered on top of that.
Apple invented that paradigm by adding keyboard shortcuts to a GUI. They have continued it by adding a command line interface and multitouch gestures to Mac OS.
The Touchbar is similar. If you take it out of the box it is simple and easy to use. But if you are an advanced user, there are all sorts of options to customize it.