Contrary to IPFS dat is more focused on what can be achieved right now while sacrificing true decentralisation, and is more opinonated with providing in its use case with providing things like versioning.
TBH, I'm not sure how a site can work without mutability.
All DHTs suffer from this issue. It's just particularly likely that IPNS's use of a DHT will lead to attacks. Making it not susceptible to this would require a redesign of IPNS's protocol.