In his travel guide, Rick writes that you could spend a week in Crete since there are so many things to see and do here, but that’s it, nothing more. He has a chapter devoted to each of several other Greek islands, but not Crete. I don’t get it.
You could spend a month in Crete and not even be close to exploring the whole island. We generally spend a month in Crete and just do one area. Our favourite is west Crete with its Venetian era cities, Heraklion, Rethymnon and our favourite Chania. Using these historic cities you can explore the surrounding areas including time at the coastal villages on the South coast.
Many people come back to Crete several times in order to explore the whole island. It has everything you could want to see and so on a Greek vacation.
Perhaps some images will prove Crete is a great destination.
Chania Crete https://www.flickr.com/photos/stanbr54/albums/72177720318408008
We no longer drive in Crete and use a great tour company Wanderlust tours
https://www.flickr.com/photos/stanbr54/albums/72177720318394812
Chania plus the south coast villages in west Crete. https://www.flickr.com/photos/stanbr54/albums/72157711266062752/
Sometimes it's pretty easy to figure out why some places are or are not included in RS guide books - usually by looking at the tours offered :-). Sometimes there's no way of knowing. RS guides are often best for first-timers to the more popular places, but they just don't offer the comprehensiveness of other travel guides.
I did spend a week in Crete - 5 nights in Chania, which I'd go back to in a heartbeat - and 2 nights in Heraklion, mainly to see Knossos and get to the ferry to another island.