I disagree with this a bit. It’s true earned value could be skewed, but it should also not be used by itself. It should be presented along with other values to get a complete picture of the health of a project. EAC, ETC, BAC, PV, AC should also be presented. Additionally any value that is significantly below or above expected should have an explanation presented as well. By presented a complete picture of facts and values associated with a project, the management and sponsors can make better decisions regarding the project.