Changing a radio/CD takes a couple seconds, and you are done. Talking/texting never stops at just one. You don't change the radio/CD every 10 seconds, do you? You glance down (which yes, is still dangerous) to change the radio, then you are done. Talking and texting keeps your mind off the road. AND your eyes, if you are texting.
All it takes is a second for an accident to happen if you arn't paying full attention to the road.