I agree with this to an but to an extent. I think its good to see a network get attacked and how it is handled. With Hive, the ninjamine is gone thus that attack vector is gone. It was nice to see how the community rose up vs what was seemingly an impossible attack to overcome. Now we see that forks can have more value, thus making future attackers think twice about trying to overtake a decentralized community.
Now, if this happened again and we needed to fork, I agree, it would be a net negative. However, we do need one "battle" so to speak before we get to a mutli billion dollar marketcap to get our ducks in a row, IE, delayed voting for newly powered up tokens, etc.
One should only need one big battle test to learn and grow to become very strong. Fool my once, shame on you, fool me twice...