Actually, since we're talking about data that can be changed and/or corrected over time, it is vital to store all this data as an initial set, accompanied by precisely timestamped changes. Because if something occurred when the data was incorrect, or with a previous version of the data, then that exact situation needs to remain preserved for posterity.

If I sign my name to a contract today and I legally change my name tomorrow, then that contract needs to remain valid. Having a tamper-proof ledger that correctly records what my name was at the time of the signing, and what my name is right now, means that no-one can claim the contract is no longer valid just because of the name change.