It is not always the case that everyone should see all projects, sometimes you want to plan the project before you give others access and sometimes you just want everyone to see everything.
Project has 3 access levels
Public means that everyone sees the project
Limited means that only the users on the project as members can see the project.
Private means that only the user who created the project and possibly the project manager can see the project.
Access level can be changed at any time!