i'm sure the demand for a free range chicken will go up after this, and i doubt many go back to the jellified taste free pap, so supermarkets will only respond to the consumer, and as long as the consumer wants it - it'll happen. The supermarkets would rather sell a free range chicken than a standard as the margin on a fiver + bird is better than a 2.50 bird.
its all about us, the consumer buying the right thing. ultimately, even if tesco were 100% organic etc they'd still only care about their profits, you cant really expect anything else i feel.
I choose to do things that hurt my profit margin as a guitar repair service - but thats because sleep is more important than a few quid
and it often turns out that the customer will come back more often if he or she knows that. fairly do's!