The top public blockchain that could be used to track pork chops - Ethereum - has been proven to be fundamentally insecure.
If there is a benefit in using blockchain to track pork chops, and if all the pork chop companies know and kinda-trust each other already, a private blockchain could keep the hackers out and implement various security schemes, and maybe even have a board that could publicly organize a rollback to undo a "DAO-hack". (As seen with Ethereum, such a "board" exists implicitly anyway even in a public blockchain system).
The ability to rollback "bad" transactions would be key in being able to comply with legal requirements, resolve contract disputes, etc. Plus having Sybil proof systems require PoW or PoS both of which could be difficult and inefficient for a market specific solution. E.g. why would people want to run a miner for pork chop trading? PoS might work though but still requires a founding core group that's trusted IMHO.
When was Ethereum proven to be insecure? It was proven that not all third party applications built on top of Ethereum are secure. That doesn't prove that they can't be secure. Arguing that Ethereum is insecure because a contract written on top of it had a bug is like arguing that the US dollar is insecure because a bank storing it was robbed.
If there is a benefit in using blockchain to track pork chops, and if all the pork chop companies know and kinda-trust each other already, a private blockchain could keep the hackers out and implement various security schemes, and maybe even have a board that could publicly organize a rollback to undo a "DAO-hack". (As seen with Ethereum, such a "board" exists implicitly anyway even in a public blockchain system).