I've maintained for weeks now in my comments that the verification/validation will always become centralized for crypto currency (including smart contracts) and the cost of verification is more acute for long-running scripts.

I've also written that I think the problem can be solved by controlling centralized verification with decentralized UNprofitable proof-of-work.

Thus I believe smart contracts are still plausible on public decentralized block chains. Ethereum is pursing the wrong design though. And they are running out of funding.