Why do elite decision makers, CEO's, boards of directors, make decisions that will certainly have adverse effects, that will literally kill people (eg. Trafigura), just to make more profit? Despite the fact that they are all already individually multi-millionaires and could not really materially improve their lives with more money?

I've ruminated on this.

I think the only reason that could explain such excess is competitiveness. To them, it is like a game. Its not about getting another yacht, its about beating the other guy. I think its the same mechanism that will drive someone to grind for many hours in an MMO or suchlike.