Greenpeace has been conducting a campaign to get certain substances used in manufacturing, that currently aren't regulated, not to be used. They have taken aim at the large manufacturers and have pretty much succeeded in getting many of the big ones to quit using these substances, if for no other reason then it's good PR. HP and Nokia and the like can point to the ratings they get from Greenpeace to show how "green" they are.
Jobs has pretty much just said he isn't going to pay attention to Greenpeace so Greenpeace has pretty much made an effort to (apparently) publicize Apple's use of these chemicals.
*shrug* Apple doesn't have to comply with what Greenpeace wants, and seems willing to take the bad PR. But be that as it may, I think to suggest that Greenpeace is somehow being paid off by Apple competitors is pretty silly. You may not like Greenpeace or their tactics (mostly I think because they are going after Apple in this case), but there is little doubt that Greenpeace is full of dedicated people working to protect the environment. I mean this is the organization whose activists would put their bodies between harpoon guns and Whales to try and protect them during whale hunts, and whose ship "Rainbow Warrior" was sunk by French commandos (killing one Greenpeace crewman) when they where trying to disrupt French nuclear testing in the south pacific. I doubt very seriously that such an organization would allow themselves to be used by large corporations to effect sales of competitors products.