Earlier quoted context omitted.
That's what they said about cryptocurrency before Satoshi came along. "You can't stop people from forging the coins in a ledger on their own servers".
And? What's your point? How does cryptocurrency prevent people from deleting content from servers they own?
Some sort of distributed validation mechanism could conceivably be created which avoids any single point of control for a piece of content. And in fact you could use the BTC blockchain as a proof of concept - post a message with your transaction that gets encoded in the blockchain. It now becomes impossible to delete or modify. It is essentially uncensorable. You could delete it from your copy of the blockchain, but the real blockchain is the consensus of all nodes, not your particular copy.