[...]The final outcome is investors, who had NO DECISION in the way this rig was operating[...]
That's capitalism for you: You fuck up, you pay.
No one said investing was a safe bet. I mean, it's on BP's prospectus for peace sake: "Risk" and "you may lose your investment in BP".
Me, frankly, do not give a shit about BP's shareholders (only 14% of which are US individuals by the way, the rest are either institutional investors or foreigners). You play the game, expect to get burned.
In fact, it is a good sign that the market is working (somewhat).