There are fundamental problems with smart contracts over public blockchains like Ethereum and Bitcoin. Can they be solved?

* No guarantee of transaction execution

* Turing-complete smart contracts are slow

* Scaling is a moonshot

* Oracles break the trust model

* Public blockchains struggle to stay decentralized

More here:

https://makebitcoingreatagain.wordpress.com/2016/02/10/5-cha...