The idea that third-party solutions will fix 0-conf... it completely throws the baby out with the bathwater. Sure, it could work -- Visa works.
But it would no longer be bitcoin. It would no longer be a global peer-to-peer currency.
Why do so many people believe this?
There are risks inherent in transactions, for all parties. Why do so many people insist that it is wrong to use third parties to manage those risks?
It's like saying that you expect your friend to not double-spend against you, so that is against the spirit of Bitcoin. Very silly.