Proof of stake is probably not a good idea on the blockchain. The fact that it's been around since 2014 and is still worth less than 2 cents per coin isn't comforting, either.
Besides, do we need a separate crypto for pot? Could that be just a marketing angle? By any reasonable standard, Bitcoin solved the primary problems of cryptocurrency. It's safe to say that it's won -- so far. If one were interested in privacy-focused coins, you might look at Zcash or Monero but both of those have security issues which Bitcoin has not -- again, so far.
