I personally believe they have too much of a horse in the race to accept that oil is not limitless, but to this point they have been proven right that new sources of oil will crop up.
In asking a question like this, I think it's worth considering the possibility that "peak oil" is little more than a myth, even if us tech people don't buy into the concept.
My sister is an exploration geologist for one of the major oil companies. Within the industry, peak oil is very widely recognized, and the general consensus is that it will happen within the next 10 years, and probably already happened a few years ago.
The myth is that we're all going to be doomed because of peak oil, they'll be widespread societal chaos, and it'll lead to the death of Big Oil. At least over the near term (~next 40 years or so), peak oil generally means more profits for the oil companies, as they control an increasingly scarce resource. Over the long term, they are potentially screwed, but good luck finding a CEO who cares what will happen in 50 years, so their efforts to finding a solution have been rather halfhearted...
Assuming you mean that as some sort of slam against CEOs: Project that slam backwards. If a CEO in 1950 had "cared" about 2000, would that have improved his decisions? 50 years really is too far away to plan, and the gulf between 2000 and 2050 will probably make 1950 to 2000 look smallish.
I'm not a huge fan of "next quarter, the world ends" thinking, but expecting 50 Year Plans is not the solution. (Even 5 Year Plans have a certain... reputation.)
This occasionally means that humans make rather regrettable choices that could totally have been avoided in hindsight, but I don't see a way to fix that without them making other regrettable choices that could only be seen in hindsight. I think it's fairly obvious that there will be a problem with the oil industry in 50 years; however, I have no idea what a possible solution to that problem will be, and I doubt anyone could until a few years have gone by.
It has crossed my mind that the "Great Filter" is simply that between here and "sustainability" is not an impossible path to follow in the mathematical probability-0 sense, but that there are so many local optima that end in global disaster that nobody ever makes it through.