To tie this back to the OPs question. Coal companies are where they are right now because of the convergence of 4 almost completely unrelated factors. First, the decrease in demand for steel, primarily in China, killed the price of coking coal. Second, the price of natural gas, an almost perfect substitute for coal in the electricity generation world, has fallen to record lows making natural gas in many cases cheaper than the thermal coal otherwise used to produce electricity. Third, the EPA has increased regulation on the mercury, SoX, and NoX which required costly upgrades to older coal power plants and there is some uncertainty on carbon pricing baked in as well. Finally the dominant players in the industry went on an acquisition spree just before the previous 3 issues became apparent, increasing leverage and decreasing their resiliency to low coal prices.
This would argue for the idea that current prices reflect what is really bad luck for the industry that all 4 of these issues hit at once, and all 4 would need to stay in place for the industry to stay as low as it is going forward. It’s very possible that coal will eventually go the way of whale oil, but in the short term it seems that a lot of independent forces need to stay in place to keep it down. Not saying it won’t happen, but odds do seem in favor of some kind of rebound. It is important to know the industry and what kind of coal is impacted by each factor however, as it's much more complicate than something like crude.