We are interested in trustless, decentralized crypto currency. That is what Satoshi pitched to us in his white paper. Satoshi's design is also flawed though.
Besides this does nothing to stop the attack monsterer outlined. Whose stake is valid? Whose is current, the reorganized block chain or the reorganized one? Which one was the reorganized one? You see proof-of-shit is self-referential and thus can't prove anything about itself.
Trustless decentralized crypto-currency is probably impossible.* (
http://www.links.org/files/decentralised-currencies.pdf)
Section 4 of that white paper is written by an idiot who doesn't understand economics.
51% attacking a coin requires it to be economic. The attacker must be able to make gains which exceed his costs of attacking. The problem for the attacker in PoW is that the attack is only sustained for as long as the attacker continues to spend on electricity. Thus shorting the coin is probably not going to work, since everyone knows the attacker has to sustain a negative income situation indefinitely. Contrasted with PoS where you only need to have owned the coins once (even if you've already spent them!).
The attacker can attempt to double-spend his coins, but the community is very like to blacklist his double-spent coins thus removing his income.
The viable 51% attack is the one that forces KYC on all transactions or changes the protocol in ways that the masses don't object to. The State is the one who has the incentive to do this attack.
Or in Bitcoin's example for the mining cartel to block protocol updates such as block size increases to increase their profits via rising transaction fees.
I have a solution for the latter two economic attacks which also will reduce the electricity consumption to an insignificant level.
No matter what the design, in the end you have to trust human beings at some level.
Not in my design.
In my opinion the security trade-offs in proof-of-stake favor decentralization. The active research in consensus protocols may give us new tools and techniques to sufficiently increase the security of PoS to practical levels of "trustlessness". The energy efficiency of proof-of-stake consensus as well as the low barrier-to-entry for participants make it a worthwhile pursuit in my opinion, and in the long run Bitcoin itself will benefit from proof-of-stake experimentation.
You are ignorant.