Honestly if we don't stop the up and coming countries from repeating our mistakes then what do we gain? A big fat nothing. A so hate this excuse of its not fair to them, well tough shit. We know better now and they can't claim to not know better either. If we get them off on the right foot it is going to be a lot easier for all of us. If we excuse them then we just push the problem off to the next generation. Of course that seems to be the aim of almost all politicians these days, push off to another generation what we are not willing to do today.
I have a more apt analogy than your pizza one.... just because Jack murders a dozen people doesn't excuse John from killing one.
Well, the developed world needs to *help* the China/India not repeat their mistakes - just crying "Stop!" isn't going to help one bit.
Look at it this way - the west needs to pay for what it has done to the environment. Why not do it through funds / technology transfer to developing countries to help them develop clean industries?
Where's Jack's punishment?