Why Is It Difficult to Gain Agreement on a Suitable

Why is it difficult to gain agreement on a suitable system for measuring marcom performance? 

A)  People are uncooperative. 
B)  People in other disciplines do not understand marketing and marketing communications 
C)  Individuals from different backgrounds and with varied organizational interests often see the "world" differently or operate with varying ideas of what best indicates suitable performance. 
D)  There is so little difference among the measures that it is difficult for individuals outside of marketing to understand them. 
E)  If it isn't in terms of dollars, others in the organization don't even want to look at it.