The heck around blockchain hacking is what I'm trying to wrap my head around as to what economic implications or importance it has. More reason I believe smart contract platforms will do the mainstream job.
I think the double-spend problem is the major one. Yes, there will be smart contracts used for all kind of stuff, I don't think the simple transferring value is the main usage in the next future, we need a change in many ways.
Double spend attack on bitcoin blockchain I can't wrap my head round it. Though I already see that only Bitcoin has to offer - value movement. Economically, not compare to Ethereum.