Many of the current "power users" are also "trend setters". If those users start switching away from Apple then it's going to be a big hit to Apple's brand value (and their ability to sell middling products and high prices).
However, I do think turning off power users is a great way for the company to shoot itself in the foot when it comes to recruitment. They really depend on a certain degree of enthusiasm to get the kind of engineering talent they want to get, much more so than money or the work environment or perqs. If they no longer inspire that enthusiasm in as many people, it'll make it that much more difficult to bring good people together to do whatever they want to do next. Unfortunately the general trend seems to be a long, slow transition from being the BMW of the computer industry to being the Chipotle of the tech industry. I'm sure all the metrics favor being Chipotle (and gosh do they love metrics), but that doesn't do anything to help make Chipotle a desirable place to work at that draws all the best talent.
I'm still waiting to see this effect in action from when Apple supposedly threw away the Final Cut Pro 7 userbase over night. That was back in 2011, 6 years should have been plenty of time to see this play out. Or perhaps the movers and shakers in Hollywood don't have as much influence as they thought.
I get asked all the time about buying laptops. I used to recommend Apple, but it has become very difficult to do so for a myriad of reasons. Lately, I have found that most people can get by with a chrome book after looking at their requirements.