Okay, okay, maybe he did not exactly say that verbatim. But after watching this snippet from an interview from Complex with musician John Mayer and fashion designer Jerry Lorenzo, you'll see immediately that his analogy aligns what we go through as photographers throughout the creative process.
One of the most awkward, skin-crawling, unavoidable conversations that you'll eventually run into is a client adamant about receiving the raw files from you. Some photographers are lax about it, most photographers I know would hold onto dear life and refuse to give their raw materials out. And that's where this whole issue arises: raws are a photographer's raw material.
Some clients just simply don't understand that, and no is not enough. They ask why. From this point, it is the photographer's responsibility not to tell them why, but to educate them why politely.
I personally use analogies. It's the easiest and most simplistic way to put someone in your shoes. And one of the most influential artists out there left a perfect analogy for you to use, on a silver platter Pun not intended.
His example may be slightly over-exaggerated, but it holds true. Raw images are considered raw materials to get the job done. And yes, there are always exceptions to any rule where clients will absolutely have to have raws or a buyout is arranged. But it is our job as a community to not only educate clients but new creatives on these issues. Yes, we may be competitive, but we can all win together.
(Note: the relevant portion begins at 15:12.)