It is often the case that cartoon scenes are staged not with the characters looking directly at each other, but instead at a 3/4 angle. It is more convenient for the animator to work this way and it could be argued it makes the viewing experience more enjoyable and the audience do not tend to register this fact anyhow.
If the characters are in profile and looking directly at each other it is difficult for the animator to capture facial expressions, but most importantly the audience are cut off, they are not fully part of the scene. Two profiles facing each other directly can also look very mechanical, it works well for cartoon strips but for animated films such as the works of Disney's it would become more regimented and less magical.
One way of overcoming characters interacting face to face is the over the shoulder pose which replicates life better. However to animate over the shoulder poses are extremely difficult, this could be due to the fact that it is hard to draw the back of a cartoon character and to make them look like they are interacting.