As I see it there are two things that may support profitability: 1) There will probably be a stream of people moving into cryptocurrencies for the foreseeable future and the hardware reliant bitcoin mining may not be their first choice. 2) New innovations. My own background has made me very cautious when it comes to accepting the first technology as the dominant one. History has proven over and over again that this may not be the case, and cryptocurrencies so far show no reason why they would be exempt from this general rule.