There is nothing which inherently says an economy has to be environmentally bad, indeed there are many examples of economic success on the back of renewable power.
I'd agree in too many cases an environmentally bad policy is persued with economic measures being given as a justification, but that is just bad policy.
A good economy can invest green, a bad economy is a collection of of people just trying to make ends meet - the environment will never benefit from this, environmentally distructive options are usually cheaper than their greener alternatives.