That's nuts.
Kids that young need a break in their day - they can't just sit there every day for six straight hours doing the three R's. Programs like art and music allow the kids to do something creative and fun (and still educational!), plus it breaks up their day. P.E. and recess give them a chance to run around and burn off some energy, and interact with their classmates and work on social skills too.
That Opencourt thing also sounds like a disaster. Forcing everyone to move in lock-step isn't the answer; the brighter kids will be bored silly, while some of the slower kids might get left behind.