Here is where your logic falls short:
In nature, without humans, thousands of gallons of oil go into the sea all the time. Much more then BP could ever let out.
The reason it normally doesn't cause trouble is because of concentration. Same reason water is necessary but can be a poison if consumed too much of, or a poison like heroin can be enjoyable if you don't over due it: The Poising is in the Dose, not the substance.
In the case of the BP oil spil, it is doing great harm because it is highly concentrated. If you could somehow dissolve all that oil into all the world's water, it wouldn't cause any damage. It would be too low of a concentration to matter. Get it?
BTW, I normally like you LY, even though you voted to ban me. But right now you are talking out of your ass (I know, I've done it

)