if you read the linked article, you see the explanation: the fourth commandment specifies resting on the seventh day. any proposed calendar that doesn't have a seven day week will never be adopted as long as religion still exists.

and even if it weren't for religion, everything is structured around a seven day week. changing that would mean a drastic lifestyle change for most people.

Then make the week 73 days long. You can rest on 7th day, and corporations would really like it.

This would be great if we had already achieved the 1950s dream of the three-day work week.