There will only ever be 21m bitcoins, and only 16m at the moment, so no 70 million were not stolen.
Secondly, when bitcoin or any other coin gets stolen, it's not due to the coding, its not due to the coin, its not due to the blockchain, its due to lack of security in the holding wallet or exchange.
As for Ethereum, it's not a fork of Bitcoin, again your information is totally incorrect.
Their blockchains have nothing to do with each other, it's like saying Pizza hut and Dominoes are linked as they both sell pizza.
Bitcoin is based on bitcoin, ethereum has smart contract ability which has enabled businesses to generate tokens for their ICo's and capital raising.
Ethereum actually broke away from Ethereum Classic (original Ethereum)
The original owner/developer went to Ethereum itself and those that don't believe in centralised blockchain stayed with Ethereum classic.
This is why the split occurred.
Let’s start with The DAO.
Long the most notable ethereum project, The DAO, short for distributed autonomous organization, raised $150m in ether – the cryptocurrency of the ethereum network – earlier this year during a public crowdsale. Held online, anyone who had ether could participate. The idea was simple, in theory. Investors would send money to The DAO and receive voting tokens, and then those who invested (and voted) would decide democratically how The DAO should disperse those funds.
Just as votes were starting to be held, however, The DAO was
hacked, attacked or otherwise compromised, depending on your point of view.
To some in the academic community, the early problems were obvious, and debates about their severity had
already begun.
But, this all came to a halt when an individual or individuals used a valid action in the code to withdraw the funds to another DAO he or she controlled.
To the ethereum platform, the action was valid to the extent it was able to be executed according to contract terms; to others who invested, it was a much more contentious action.
Skipping ahead, the ethereum community eventually held a vote, with the majority of participants agreeing that they wanted to change ethereum’s code to get the funds back to investors – and away from the attacker.
