Given the shear number of people that use Facebook and the number of those using it for news the relatively constant stream of "miscalculated metrics" is alarming. The miscalculations can and do shape opinion and move events in the world. With incorrect information or misleading data the public has an even harder time knowing the truth and forming informed decisions.
I realize that Facebook can run its metrics anyway it chooses but they are getting a reputation for slanted trends that I would worry about. If you are branded untrustworthy, your done.