It's a good final social check on bad behavior. I think Vitalik as written about this (I'm pretty sure I read about it in one of his long form posts).
The DAO "hack" was a bit different from this, around 14% of all Ether were in that contract. There isn't going to be another rollback, especially not for something like the here discussed attack. Trusting third parties is risky. It's like taking your money out of your bank account and sending it to a bank in Nigeria. Things can go wrong, the chain can't be rolled back every time someone loses money. People have to be more careful.
There is increased risk moving stuff off chain to third parties.
People focus on the algorithmic aspect of cryptocurrencies, but this is simply the weedy details that enable certain properties of interaction. Nothing terribly interesting has happened here since the initial idea of using proof of work to regulate authorship of a blockchain. It is the social aspect that has been interesting to follow. Alt coins, forks, and the enduring primacy of Bitcoin.
This should really be phrased "which is why the fork is called Ethereum and the original chain is called Ethereum Classic". And the majority (of what?) really had only indirect input - the exchanges decided which chain would get which ticker, and if they'd kept ETH=the original chain, it would still have the name Ethereum.
Hahaha, no, the wealthy sided with the move. Of the 82,054,716 ETH in existence, only 4,542,416 voted, for a total voter turn out of 5.5% of the total supply on 16 July 2016; 3,964,516 ETH (87%) voted in favor, 1/4 of which came from a single address, and 577,899 ETH (13%) opposed the DAO fork.
Vitalik and his friends stood to lose a lot of money, and being the biggest players in town with their premined shitcoin, voted against them losing money.
What people continue to use and build on is the other.