Erm... the worst thing someone in charge of marketing can do is give everyone a horrible impression of your game and/or flat-out lie about its design.
The people who make commercials for Ford don't get to tell Ford engineers how to design their vehicles and products.
"Nebulous term like marketing," he says...
Silly goose.
OK I am complete satisfied with the answers provided by @badler. That said when ever you see product placement on tv/movies/games, guess what? Marketing! When your email address is being sold by your insurance company/cellphone carrier/credit card company, guess what? Marketing! If you think that coke or nike doesn't have redline privileges on how their product is shown in any media, think again, marketing. Any Disney animated movie, while story is one component, marketing is working overtime in tandem to make sure $s...Work in LA or SF for a bit and you will see how marketing does or can influence design decision. Your ford example is flawed. Ford doesn't ask its ad agency what car to build, but ford execs sure as hell asks the internal marketing team what will sell, and then designs and build cars accordingly.
Any how I asked the question I wanted, and got the answer, I am perfectly content.