I knew as soon as I read your comment that multiple people would object to your use of 'conservative' instead of focus on the point (as if the opposing political views lack integrity, values, respect for law, etc).

In any case I think the reason comes down to money/power structures and short-term thinking. We have two corporate controlled parties with one that is wholly owned and the other which allows a tiny sliver of dissent. Fossil fuels will never completely go away but anything that questions the entire infrastructure (worldwide, including the need for bases in producing countries), is seen as a threat to the status quo. In this way I don't see it as any different than teams protecting their turf in a large company which stifles innovation.