I agree. I have been touting Myriadcoin as one of the biggest innovations in the PoW cryptocurrency world. It is definitely a step forward. Unfortunately, it still doesn't change the fact that a lot of electricity and processing power is wasted in the process. Pretty much all scientists agree global warming is real and PoW only accelerates that. I see PoS or a variant of it as being the ideal solution for consensus mainly for this reason. Why increase emissions unnecessarily simply to reach decentralized consensus when it is not needed because PoS is sufficient at performing the same job? Also.. all of the processing power could actually be used to do something useful to society instead of simply securing a block chain, such as solving cancer or assisting other scientific research. Primecoin is a good example of a PoW algo that is actually useful to society.
These are my biggest concerns about PoW, not the centralization of it. All systems.. PoS and PoW.. inevitably tend towards centralization eventually. PoW tends towards centralization in mining pools and large farms setup with cheap power which utilize the economies of scale ASICs provide. PoS tends towards centralization with the need for check points to prevent certain attacks (or at least in the current variants of PoS.) DPoS works on the realization that all systems inevitably tend towards centralization, ad it gives you a way for stake holders to control that centralization. Stake holders choose who becomes a delegate, with PoW you cannot choose who secures the block chain.. whoever buys mining power can do it. This helps keep nefarious actors out. Also, you can vote in developers and people creating important core services for the coin as delegates to compensate them for doing so. Therefore, a DPoS coin can hire employees that work for the cryptocurrency... PoW can obviously only do this via donations. The use of only 101 delegates allows block times to be reduced to a little as 10 seconds and process many transactions a second.. something that is very hard to achieve (maybe impossible) with PoW. There are many benefits of DPoS over PoW in my mind which far outweigh the highly unlikely attack vectors, and that is why I support it over PoW alternatives.