Except for the stock market crashes of 1929 and 1987, the dot-com bubble, the housing bouble followed a crash, the tulip mania, ... Markets are not always rational.
Currently the Amazon rainforest is being slashed and burned for a mere decade or so of beef production, before the fertility is washed out to sea, the vegetation dies, the continental transpiration cycle shuts down, and that land too is desertified. A similar process has already happened the Middle East, which was forested in accounts as recently as Napoleon's campaigns.
I liken it to the crew of your spaceship busily axing away at the life support generators... :-\
Crashes are expected in the market theory. Crashes are actually healthy outcomes that get rid of mal-investment. There could have been much less severe crashes in the situations you described if there has been less government involvement (there is ample evidence of the government agencies and the FED being involved in the dot-com bubble and the housing bubble).