That is not a universal phenomenon. In fact, it's far less universal than the basic writing rules that you decry.I guess the more you know about art, the less you can enjoy it so obviously it pays to stay as ignorant as possible.
There was a period of time, after I did a lot of editing, when I started finding prose problems in books I was reading. I was afraid this would ruin books for me. Guess what? The feeling passed. I was able to shut off the editor's brain and enjoy books like I used to. And it also made me appreciate truly good prose a lot more than before.
Does the painter lose the ability to enjoy paintings? Ask any author out there--did becoming a professional writer cause them to dislike reading? These people learned the nuts-and-bolts behind the art, but that did not take away from its magic.