I think you are missing the point of much of environmentalist critique of capitalism. That point is about a wasteful use of resources by a small segment of world population while the majority remains in dire poverty. This is essentially the same argument as the bearded one launched against capitalism, so I do not understand your opposition.
I agree that there are certain primitivist and luddite strands in the US, and I presume UK, environmentalism. Also anti-fossil fuel sentiments are often thinly veiled nationalism (dependence on "foreigners" and their resources). These are essentially the same tendencies as utopian socialism in the 19th century, or for that matter attempts to protect native US workers from foreign competition. I am sure you would object if someone used the primitivist, luddite, utopian or national socialism in his broadside against socialism in general, wouldn't you? So why attacking environmentalism in the same fashion?
I agree that environmentalism is a critique of capitalism by proxy, and those who want to call a spade a spade object to such indirectness. But the point is that much of the traditional critique of capitalism lost its currency altogether - and most people see it as purely academic crackpottery. Rewriting that critique in the langue of environmentalism - which generally falls on much more sympathetic ears than the old style communist harangues - is thus a good thing, no?
Finally, a point of clarification. I do not object to fossil fuels per se, but to the device that these fuels made possible - the automobile. To be sure I do not hate the automobile per se - it is a wonderful piece of engineering - but the life style it made possible: suburban sprawl, long solo commutes, high cost to individuals (in the US, cars expenses exceed those on housing), subjugation of individuals to the army of mechanics, salesmen, policemen, etc., destroying the viability of other transportation modes, which practically immobilizes those who cannot drive, inherent high risk of injury and death, high noise level generated by both engines and sound systems, to name a few.
In short, I hate the US lifestyle with passion. I also understand that the factor that made that life style so despicable is not capitalism (for European capitalism created far less obnoxious life styles) but the land use made possible by cheap gas. So my wish is not that they stop pumping oil, but that they get rid of the "American life style" altogether. Expensive gas, say $5/gallon, will be the first and important step in that direction.
Wojtek