The thing is that the operation that you are showing is the first one from HF23. Without it Hive would not exist (it would just be steem). Is there another operation before this one that shows that you owned hive?. The answer is no, what you owned was steem (and you still do).

Hypothetical question, if I copy the code and the transaction history from steem (or any other chain) and create a fork that transfers all of the funds to my account on a new chain is that stealing?

You still have the same balances on the old fork and as long as other people (especially exchanges) recognize the old version of the code as valid the answer is no...it is not stealing. I am just a crazy person saying to the world that I own everything.

The only effective way to create a contentious fork on a DPOS chain is to replicate everything except the stake that is opposed to the new version of the software (if you want to preserve the history of the old chain). AND the only way that you can remove the stake in question is to execute an operation that does exactly that (otherwise the hardfork doesn't exist since the stake that is being nullified is controling consensus).

It doesn't mean that you owned the new coin prior to the hardfork. I know that this maybe triggers negatve emotions but what you have to account for is that hardforks on blockchains are just code changes that don't mean anything per say until a group of people start to recognize them as valid. If no one gives these code changes validity it's just a bunch of people on the internet saying non-sensical things.