Its actually better to have channel on the left (for right handers). When you hold a remote reach for the left buttons and then try the right. You will notice that you have to work harder to reach the right hand side even though its closer. Your thumb has to pull back more to reach the right buttons. If you suffer from carpal tunnel or have wrist pain you can tell the difference right away.

Since channel buttons are more frequently used its best to keep them on the right hand side.