This has changed quite bit in the last 5 years. "Coding a game" is not just using a proprietary program to write pinball rules any more. Good rules are certainly cool, but there is so much more to a release now, since the standard of what is included in a relevant, fun machine has certainly changed.
With new game elements comes new creative designers and coders, incorporating many new elements.
-Color changing lighting
-Full video animations
-Even things no one notices like the entire operator menu needed to be revamped to use an LCD display
Then there is the actual SOUND and GAME code that incorporates all of these elements together. This is no easy task. I hope that people do realize that there is no longer one single person that designs or codes the game, making certain it works the way the TEAM of designers intended. There is a huge team of people, some of which have only worked together for a relatively short period of time or have never worked together at all. Then you have the testers. If they suck or are not committed, they will not find the problems in the code.
A "coder" and a "pinball designer" are not the same person. Yes, they could be the same person but most often, they are different teams of people with one "lead" for a project.
When you consider all of these things, I am impressed that a game is enjoyable at all. So many people working on a project that are committed to creating something amazing is what it takes.
Let's not forget this. One single person could never be responsible for or be credited for single handedly creating (or coding) a great machine, or a terrible one in the current market. Just look at the list of credits on a recent Stern machine.