Civilizations are ephemeral compared with species. Humans have lasted at least a million years, but there have been 30 civilizations in the past 5000 years. Humans are tough and will survive; civilizations are fragile.
Over the years these proposals have been in different forms; create a book, set of books, stone tablets, micro-etched metal disk, or a constantly updated wiki. I really like the idea of creating such a record, in fact the Rosetta Disk project was our first effort in this direction. These Doomsday Manuals are a positive step in the direction of making a softer landing for a collapse, and the people creating them (like ourselves) are certainly out to help people. It took millennia for the world to regain the technology and levels of societal organization attained by the Romans, so maybe a book like this would help that.