Last two paragraphs first: You are making a logic error here. A human at a certain level of (whatever you want to call it, productivity, success, wealth, whatever) will want a certain lifestyle level and will use vastly more resources to achieve that lifestyle in a less dense city. You can see that comparing pretty much any set of cities in the world if you stratify by income and look at resource usage/co2 output/whatever. Environmental cost of importing resources is also pretty low as long as you have good transportation methods in use (i.e. shipping or train with trucks minimized). So, if you actually want minimize impact the correct thing to do is to expand and densify cities until the decrease in environmental damage per capita from increasing density equals the increase in environmental damage from importing resources. This means the best setup is a dense city with a decent resource feeder area around it, not a self sufficient area with a less dense/more suburban city.

Now for the first paragraph: This is kind of the point because maximizing use generally means more density, which means more opportunity to minimize use elsewhere. I did outline one situation that I thought was unfair and should be addressed, which is the situation where you buy land zoned one way with a much lower value only to have it zoned another way on you that makes it a lot more valuable. Other than that specific situation, I don't agree with you that your first paragraph is a problem, it's a positive feature.