"When the Ninja-mine was discovered the coins should have been forked off."

The ninjamine predated Steemit, and even witnesses. It was the very first step in creating the Steem blockchain, which later supported Steemit the dapp, and blocks being created by witnesses, instead of PoW mining tokens.

No one came to Steem without the ability to do due diligence and be aware of the size of the Stinc stake. Not until last year was credible consideration to forking off the founder's stake entertained.