Do you really believe that after this revolutionary creation, people will simply forget it? That this innovative technology will be gone just because the government says so? That we'll let slip the PoW mechanism combined with a chain of blocks containing immutably information?
As much as I think almost all altcoins are either trash or scams, bitcoin is not the only possible incarnation of a decentralized peer to peer currency. The idea might never die, but that does not mean that bitcoin is invulnerable to attack.By attacking Bitcoin, you actually attack your own wealth. Masochism... 
There is no requirement to own bitcoin to attack it. A government which sees it as a threat to their fiat monetary system could be attempting to preserve their wealth by attacking bitcoin.Which ones do you have in mind?
No idea. I don't really follow altcoins very much. The only altcoin I hold is Monero, for obvious reasons given my feelings regarding privacy.Ethereum Classic was made due to a hack of a third party project.
Ethereum Classic was made because a majority of Ethereum developers decided they wanted to reverse some transactions which had taken place on the Ethereum network, not unlike a 51% attack. Those who decided that developers shouldn't be allowed to reverse transactions they don't like forked the network to create Ethereum Classic.