Hi Xbeast. Greed, ego and dogma, for a start. I am also guilty, of in the past, being partial towards some prospects over others. That is why the PFS, DFS and go/no go steps are undertaken by the directors of a mining company. I have explained these steps in a previous post. Only once a risk assessment has been carried out, and all directors agree that the "go" option is most likely to succeed, do they actually pull the trigger, It is impossible to mitigate against all risks but that is a line for the directors to draw.
Of course, no bank will be willing to finance a mining venture, unless it is backed up with convincing numbers (+/-10% accuracy required for ALL inputs). It is possible to bypass the DFS and the go/no go steps, if the downstream industry assumes some of the risk, such like Burwill has done. I believe that they are astonished at the rate at which their investment was swallowed up and the other $25m committed by Weier. I don't think that they appreciate that it costs over $10m a month, just to pay all of the routine bills. The cost of running a similar Chinese operation is orders of magnitude less, I know because I have visited a similar Chinese operation. They recover every scrap of economic mineral out of their plant feed.
We also have to remember that Burwill and the surviving directors of A40, only came together as a result of evolving circumstances.