Cost and the value to the consumer. Ford has used this key for quite a few years now. The consumer is (I imagine) more motivated to look a new car based on its design and features. After all, they only see the key once they've made it to the test drive.
"Our inventions are wont to be pretty toys, which distract our attention from serious things. They are but improved means to an unimproved end, an end which it was already but too easy to arrive at...." Thoreau