Here's why:
* Cart usually refers to a wheeled vehicle used for transportation.
* Writer refers to someone who creates written content.
Possible interpretations:
* Cartwright: A person who makes or repairs carts.
* Cart copywriter: Someone who writes copy specifically for shopping carts or online checkout processes.
* Cart writer could be a slang term for a copywriter who focuses on writing persuasive sales copy.
Without more context, it's difficult to determine the exact meaning.
If you could provide more information about the context in which you encountered "cart writer," I might be able to give you a more specific answer.