because base metal and iron ore offtakes often also involve the offtake partner taking an equity stake and sometimes board member position in the mining company they are off taking from to ensure future supply - look at who the share holders or proportionate mine owners are in companies G1A or FMG or MGX or WSA.
BML May give up a small piece of the pie but more than compensated for by having a larger pie to eat from and a pie that is held by strong hands so less likely to be stolen from circling black birds .
