This book has nothing to do with reinforcing gender roles.
It does breifly touch on how to talk to girls, from the point of view of a seven year old pretty much. It makes it plain that bouts of flatulence are not as impressive to girls as boys might think.
But it is designed to point out to boys, and their fathers, that there is more to do than simply play video games and watch dvds for fun. It has tips for fun things to do like learn to build batteries, treehouses, and other sprts of things that the author and generations of boys did in times past.
I have two sons, and a daughter who are getting a copy of this book to share. The science, the history, and the neatness in it are just way too cool.
Besides, there is almost an entire page that describes the value of playing D&D, and Warhammer gets an honorable mention as well. This is a book that embraces childhood in defiance of those that would have us feel guilty about being dirty, inquisitive, eager, adventurous children.