"Is it just that the particular individuals involved have no interest or background on eco-stuff?"

Yes.  As you commented awhile ago, most people, including leftists, don't give any priority to environmental concerns.  By the time things get so bad that those people have to give the environment the priority it deserves, it almost certainly will be too late.

While it could be argued that the mainstream commentaries do not concern themselves with environmental or energy concerns, I believe that almost everything we read about today is intimately conected to and centered on both of these issues.  I suppose the biology and ecosystem paradigms that I use as models for understanding provide me with very broad definitions of both of these terms. So, I suppose I would disagree.  However, we haven't really called these issues environmental issues. We have other names for them.

I would say that the problem isn't that the environment doesn't have enough commentary, it is that those commenting don't realize that they are indeed commenting on the environment.  

I think part of that problem is that the enviroment is taking a back seat to the war and nuclear proliferation. Liberal blogs make occasional note of the Bush administration's enviromental policies but usually only one complaint/fault in a long list.
We are living in "interesting times".
(If you recall the old Chinese curse.)