and yet we don't read about Constellations and DC6's being deliberately flown into mountains very often back in the day so what is different now?
Aircraft were being flown into mountains all the time though - far more than now. Black boxes were less sophisticated, or non-existent, so it would be harder to tell after the event what the cause of the accident actually was. And because there were so many more accidents from all the 'classical' pilot error and mechanical causes, as a proportion of the accidents they may have made up a smaller percentage and therefore been easier to dismiss.