I agree it wasn't a bug in the protocol. However, it was an issue that people in general weren't aware of, and even the official tutorial code on ethereum.org had similar vulnerabilities. For that reason I think the fork was reasonable.

By comparison, Parity's wallet bugs were just a result of carelessness, and independent audits probably would have discovered them. Consequently, the community strongly pushed back when Parity tried to get a fork for the second one.