Would you consider the use of the most powerful GPUs in the world for gaming, more wasteful than running those GPUs to sustain a global currency? Those GPUs are currently being used for fun, where the hashing power could have been used more productively to sustain a few thousand global Crypto currencies. 

Most of the ASICs in development today are geared to energy efficiency and the mining farms are powered by renewable energy sources, like hydro/Wind/Solar energy.