ZCash may be a good investment after all, if it continues to provide real innovation to the blockchain space. But, if it's all based on hype without delivering real usability, then I'm afraid that it will die within a short time frame. I think that there are other altcoins which are more promising to invest into than ZCash.

I've heard that Ethereum will be integrating ZK-SNARKS which will bring privacy for smart contracts. Also, it will be upgrading to PoS, among many other things which makes ETH a better investment than ZEC in the long run. Therefore, it all depends on how many people are interested in ZEC as a privacy-based cryptocurrency for their daily payments.