If you think there aren't "rules" to graphic design that are typically followed, you're fooling yourself. Just like there are times when the best answer to something in programming isn't necessarily the intuitive or logical answer.
The book I referenced is a great resource in explaining why this is true. Part of the brain sees things symbolically, so that when someone is drawing a face for instance, they don't draw what they see as the eye, instead they substitute a symbol in its place. To the person drawing this might look OK, but to other people it looks like a kid drew it. To get good at drawing, you have to shutdown that symbolic part of the brain, and just draw what you see, not what you think you see.
A good designer will know when to break the "rules". Like a good coder will know when to hack something together, rather than obsessing on architecture and keeping code "clean". Its all perfectly logical. Except when they said "Fuck it, it will work better this way."
Massimo Vignelli had his grid, but David Carson threw it all out the window. Coder X might spend a few days writing his code in what he thinks is a clean, maintainable manner, while Coder Y might hack it together and worry about maintenance later. In both cases, both approaches can be right.
The difference is that one change is done purely for the improvement of the aesthetics, while the other is done because of some fundamental disagreement about the underlying engineering principles. One change is done irrationally because it "feels" right, while the other is a disagreement on the nature of the rules (or a lack of understanding of the purpose of the rules). But there are rules (whether or not they've been articulated).
Usually when programmers "hack" things, they cause a raft of other problems in their wake. As software development progresses from an art, to a science and onto engineering, hopefully the desire to hack at things will diminish. We can actually reliably build complex systems, but only when we choose to think about the right way to do it, rather than just react to our environment. Personally I don't think good programmers "hack". They build. It's very different.
It's best to realize that a good Graphic Designer can outrun a programmer in the same way that a good programmer can outrun someone that can't think logically, although some programmers seem oblivious to this. If you need good Graphic Design, it is best to hire a professional that is well suited to the task.
If you really want to try to bridge the two worlds, then a degree in Graphic Design is a good idea. Drawing, painting and photography are also good hobbies that can help you develop an aesthetic. A good reference to start with (and explain why logic and rules fail) is Drawing on the Right Side of the Brain. It's an old classic, but helps in understanding how our brains interfere with our perceptions.