Because coding literacy is as important as textual and number literacy. Basic understanding of code, and how to create codes has become increasingly crucial ability to be able to cope with this digital world where reality can be constructed through binary symbols and representations.
Coding subliminally will teach kids to follow rules and being consistent while also being critical and creative as well. Constantly being challenged to solve problems through coding, they will develop thinking instruments that will be ready to keep up with the rapid growth of technology. Kids in this era should not be taught to learn just one thing, but should be taught to be able to learn different things in short time. They should be trained on how to adapt with rapid changes, after they have solid ground of necessary fundamental knowledge.
Other important thing is that the world is lacking programmers. Teaching kids to code hopefully will equip them with basic skills they need to find job later in their life. This is an effort to give them earlier start off, so they can reach higher when they grow up.