Musings on all things green-y

Has anyone else ever pondered the inconsistency of "Let's grow soybeans as a renewable resource! We can make all this stuff from soybeans instead of fossil fuels!" versus what to me is the more credible argument, "Why waste so much land growing beans no one will actually get to eat when it could be growing FOOD?"
Bear in mind, these are both "environmentalist" arguments. And mutually exclusive ones, at that.
Reading eco-friendly whatnot is rather like navigating the arguments for and against capital punishment and abortion - there are a lot of contradictions, and a limited few viewpoints that are not self-contradicting. Argument 1: Life is sacred, in or out of the womb - so much that if you take a life, you forfeit your own. Argument 2: Life is sacred, in or out of the womb - so much so that even IF you take another's life, you should still not lose yours. Argument 3: Life is NOT sacred. If your crimes warrant it, we will kill you. If your birth is unwanted, ditto. Argument 4: If you're an unborn child, your existence is dependent upon your mother's whim. If you're a serial killer, you should be able to live as long as you want.
Argument 1 and 2 are both consistent and logically sound. Argument 3, as reprehensible as it may be, is still at least consistent within itself. Argument 4 is pure nonsense.
A lot of environmentalists want to have their cake and eat it too.
IFF (a notation meaning "if and only if") your contention is that cars powered by gasoline are ecologically Bad, using soybeans in their construction does not magically make them Good.
IFF your goal is to reduce electricity usage, and so you're unplugging all your electronics when you're not using them - why then are you plugging in your CAR?
IFF your contention is that fields used for production of corn and soybeans that will never end up in a grocery store is a waste, then trumpeting the "virtues" of biodiesel and corn-and-soy-based products over those produced using crude oil is just plain silly.
Those are only three of the contradictions that have wandered through my brain recently. There are many, many more.
There's an "environmental" group here in my city called "Food Not Lawns". I'm a member. They're not out to do anything radical or bother anyone else, they just grow their own food, eat and shop locally, try to consume fewer resources, and strive for a more self-sustaining lifestyle, which just kind of makes sense regardless. This is what brought to my mind the contradicting arguments of "we should use corn and soybeans in place of petroleum products" and the F.N.L. standpoint that it's a waste of land that could be growing local food instead of being used to make the fuel needed to transport food in from elsewhere. Personally, I think the second is the sounder argument, but what do I know - I'm just into things that make sense. And I can't eat or drink biodiesel.