Honestly no idea, except just pointing it out when someone mentions it.

The whole ECC recommendation is due to ZFS (unlike other filesystems) providing guarantees to data correctness, but as you know while ZFS can discover data corruption on the disk thanks to checksums, it can't guarantee data correctness in RAM because because as any program it is bound to trust it. That's why ECC RAM is highly recommended.

I think there is some confusion about the impact of bit flips on reads and on writes. Those are separate cases. That blog post is absolutely correct, but it talks about writes. People here are talking about reads.

The forum post and blog both state that data also gets corrupted even more during reads. They also use strange assumption that data would be written to RAM ignoring byte boundary (i.e. shifted by 4 bits).