#4 Shane McMahon returning to WWE RAW is a surefire way to boost viewership numbers
Whether or not your opinion is that WWE RAW is reaching creative peaks or valleys, the fact of the matter is that fewer people are watching WWE RAW than at any point in the history of the company. One can always create new stars from the existing WWE roster or alternatively, Vince McMahon could rely upon the stars of the past such as Shane McMahon (and Randy Orton in the WWE Championship picture) to boost ratings.
Yes, I know that a lot of the current WWE audience may not necessarily want to see Shane McMahon back on WWE RAW, but you have to understand that he is a familiar face to WWE RAW viewers around the world and when one is switching between channels, there's a big chance that someone will stop for a moment to catch a familiar face. While it may not raise viewership for WWE RAW by many millions, there's a big chance that it will go up with Shane McMahon.