I'm not sure I 100% agree with this mantra. At the very least, this advice may not be good for everyone, and possibly good for no one. I may be misunderstanding the intent of the post, but it kind of sounds like you are saying its better to just incorporate key changes into your swing and move on than to understand the reasoning behind that change. One thing I have found over the years, and this isn't just with golf, but with anything, is understanding why means you are much more likely to remember it. I am an engineer so I can probably think of a bunch of weird examples where understand how something works helped me understand it overall use a lot better. However, one of the best analogies I can come up with comes from my years of playing the piano. I was never great at piano, but one thing I do remember one thing about learning pieces. You start out sight reading, practicing each and by itself slowly. Then you slowly put the hand together, measure by measure, section by section. Then you start to speed it up, still looking at the music as you play. Slowly you memorize the piece where you don't need the music. You still think about whats coming, as you are playing in your head you see the notes coming, the tempo, how each fits together. This is where you kind of have to be careful. Since I wasn't very good, I would often just play and play and play without music until the piece went from being memorized in my conscious brain to memorized in my subconscious--what people colloquially refer to as muscle memory. I could start the piece and literally check out and my hands would just do their thing. I wouldn't need to think about what was coming next my hands would just play. However, this invariably led to a situation where I actually FORGOT the notes but could still play the piece. If you grabbed me halfway through the piece and said "what actual notes are next?" I wouldn't be able to tell you. If you said "ok fine you may not be able to tell me but can you play them?" I wouldn't be able to do that either. I would have to actually start from the beginning if I got stopped in the middle. If I every made a mistake or my momentum got stopped I couldn't just pick up in the middle. I'd have to go back to square one. All because I forgot the way the piece worked and I was just being, as you put it, a "stupid monkey."
This is my long way of saying I don't see how you can practice correctly and maintain a good swing without knowing why a swing the way it is. I don't see how you can take feedback from a round or a session of hitting balls and make the right corrections if you don't understand the why and the how of golf. If your ball start hooking like crazy and you don't understand ball flight laws and the effects swing path and face angle have on the ball, how would you know that you were flipping your wrists or getting you hands ahead of your hips or whatever it might be? And that is just basic ball flight stuff. I often hear how the short game and the game of golf in general is about creativity. How can you improvise if you don't know what does what? If you don't know how moving the ball back and forward in your stance affect trajectory and spin, how can you punch the ball under trees or keep the ball down in the wind?
If your point is merely to say don't be a tinkerer, then ok. I agree that constantly making tons of tiny changes to your swing isn't productive. Perfect is the enemy of the good, and your swing will never be perfect. Professional help is good, but we don't have 24/7 access to someone to say "hey for the last 3 holes all my shots have been going high and fading, what do I need to fix?" Or even better, "hey I'm hitting off pine straw and I have to keep it low to get under those trees but it also has to carry that bunker and then stop on the other side how do I do that?" You need to know how your tools (the 14 clubs in the bag) can be used by you to manipulate the ball based on the situation to do what you want. Doesn't seem like something a stupid monkey can do, unless he memorizes every possible situation, lie, obstacle, distance, weather conditions he will ever experience and memorizes every possible kink in his swing that could happen and the exact fix for it.