If you read the entire thread, I think there were a few deep sins involved in, notwithstanding technical problems:
1. Hype and committing to a model naming scheme based on it.
2. Sama making decisions based on not liking being made fun of on twitter (1/x)
Honestly I think I can do a decent postmortem of everything which went wrong with 5:
1. Two and a half years ago, long before they had any idea what it would look like, they were hyping 5.
2. They trained Orion as 5, expecting big benefits from scaling pretraining, but (1/x)