A couple of reasons, let me clarify first by saying that I’m speaking from a corporate environment.

1. When you make a new excel sheet for a “standard” purpose you immediately create doc control problems. Where is it stored? Who is the owner? How do you know what the latest rev is? What if the rev is not updated by the last user?

2. If the review is checking for existing documentation you are likely creating double work, especially of the review requires the information to be “translated” into a format that will only be see for the review purpose.

3. Finally there are better tools for project and portfolio management. Projects need “One Scope” by repeating information in separate documents and locations for different audiences you run a high risk of inconsistencies across the communication, and causing confusion and conflict when the different parties meet to discuss the scope among themselves.