Even though the author has a valid point on what Apple is selling, there is no reason besides a completely selfish one on Apple's part for them to disable features and discourage customization.
They should be able deliver everything the article mentions as their strengths while not disheartening power users if they tried.
This is a normal feeling.
I think that everyone goes through the apathy stage when they get "comfortable".
The trick is to figure out your motivations and use them to get yourself feeling less secure.
Sometimes, I confront my ignorance of topics outside my work scope. I look at the amazing work people are doing in Haskell or read about a new startup.
Thinking about how much I don't know and all the things I haven't accomplished but would like to keeps me going.
If that doesn't work - go to the gym and workout as hard as you can. You'll remember what it feels like to put your full effort towards something.