If anything, Apple has shown us that design does matter and I feel like software (especially websites) is getting more usable over time. Your discontent over changing UIs seem like those of a long-time user upset by someone moving their cheese. I didn't like Chrome's spartan UI at first, but it won me over.
You have the basic Cocoa interface with accessibility features. You have OS X' default helpers, mostly the "Help" menu that allows you to search for menu items. You have AppleScriptability for lots of apps, even some third-party apps written by "designer" folks like Things. Then there is Automator. And below all that, you are free to do whatever you want from the Terminal.
I hear this argument all the time, but I don't get it. Besides software that 3rd parties choose not to write for OSX, what functionality is possible on Windows but impossible on OSX?