I think the author makes a good argument about how data structures and objects/classes are different.

I'm one of those people who designs the data first and then the code. But when you design the code, you shouldn't be making it a one-to-one mapping with the data.

When you design your classes, they should be the best representation for the programmer to use and not necessarily just identical to storage format.

As well, the most convenient structure for the user of your classes is most likely not the best format for storage.