Erm... Bonio, whilst frequently quite irritating - and I'm not convinced this whole 'theft' thing isn't a publicity stunt - frequently visits Africa and other impoverished places on fact finding missions. Moreover, he publicised the Jubilee 2000 campaign to drop third world debt and got George W to donate $5 bn in additional aid to Africa.
I think it's certainly possible to argue that getting into bed with people like Bush is a flawed way of improving the lot of the poor and powerless - Bush got a photo op and gained a bit of cred, for example, but on the other hand, the bloke at the other end of the world with a bowl of rice in his hand is likely to be grateful for small mercies.
Chris Martin is a tireless campaigner for FairTrade, so I think you're a bit off with having a pop at him too, regardless of what you think of his music.