The problem with oil companies not using the sources they have is that the market inherently is giving them reason not to do it.
A huge company isnt run by a one or two people deciding, based on their personal opinion, ethics etc., what to do. Usually once you run a decision through enough people, a purely efficiency-based, self-interested result is normal, as any individual qualms or issues with it are smothered by all the other people, who in turn have their personal opinions relegated to at best a note on the bottom of the meeting summary.
And nobody is at fault, because "the shareholders" decided, right?
Now, in simple terms, if an oil company is making a killing drilling ,for the sake of simplicity, 1 million barrels per day, at a cost of 30$, and can sell them, due to high demand etc. etc. etc. for 120$, thats pretty damn profitable.
Now, in order to feel convinced they should invest in more refineries, drilling platforms and whatever else is needed to open up new sources, that has to raise their bottomline by at least enough that they get more money out of it within a reasonable timeframe, say 4 years or so, than out of their current production.
Since Barrel prices would fall if there was more around, its simply not profitable, considering the investment needed to open up new oil sources, to produce more oil and have the price drop.
Individually, I am sure each of the major shareholder guys will claim they are interested in the good of the people, in lower gas prices, yadda yadda.
But as a sum of all decisions, the companies themselves will not change course without being forced.
Which is the point where governments must step in. Its bad enough a vital resource today is controlled entirely by corporate interests, but when they purposefully, or simply by acting like corporations have to act to protect the interests of their shareholders, cause financial problems for millions of people, thats the point at which someone with power has to do something, because thats how the entire system is supposed to work.
Capitalism doesnt really work well when it comes to vital resources, without governmental control or at least strong influence, because todays corporations arent really ABLE to act, I dont know, ethically. Its not an option, the way they are structured, with shareholders living all over the world, arguably not giving a damn for the misery of people in some different country.