The thinking probably goes along the lines of:

1. The oil will run out "long" after current oligarchs are dead so they don't care
2. Even if it is diminishing sooner than anticipated, would you want to be the one to tell oligarch #236311 that his oil fields and money are about to run dry, pissing him off? They're surrounded with sycophants and suck ups who have their own money wells to run dry
3. Solar and other renewables have just enough real problems with them that aforementioned sycophants can blow it out of proportion and frame them as bad investments.

Systematic capitalism plus human greed heavily incentives short term thinking