It doesn't. I probably didn't communicate properly. I think the first rule of bonsai REALLY IS that if you like it, that's all that should matter. However if you take your tree to a bonsai show, they will apply classical Japanese rules to judge it and if you don't conform to the rules your tree will not do well.
I also keep and show koi. I know how judges judge koi, what the important characteristics are, and how many points each of my koi would win in a koi show (accepting a small variability based on personal biases of the individual judges). Some of my koi have won shows (and hopefully will again this Summer). However I have plenty of koi that I like a LOT that are not "show quality" and I will never enter them in a show. They have individual characteristics that I find to be intriguing, or just plain unique. All that matters to me is that I like them. If you ever came to visit, by the time I was done expanding upon their virtues, you would like them too
So I am not trying to discourage anyone from having their own personal taste in bonsai. However I think it is important to develop a classically-trained eye so that you can at least evaluate bonsai based on Japanese design criteria. Otherwise you will always feel like you are slightly out of step with the hobby - like people are speaking a slightly different language. (I'm not saying you personally, I mean the generic "you"). I think there is a huge difference between someone breaking a rule of bonsai because they WANT to, versus someone breaking a rule because they don't know any better.