I think rather than dating itself, what I meant was that I am more forgiving of that particular unthinking assumption in a book written in 1975 than one in 2011; it would bother me more if the book had come out last year.

When I read it for the first time, I was young enough that I took everything for granted, but it really struck me this time that the main character was the mom. And also that she was one of the "ordinary" characters: that there were super-smart, super-strong characters, and they were secondary. And their story was fascinating, but tangential to the main arc of the book, which centered on getting her house of danger of the plow.

In some ways it feels like it could be the model for a fantasy story set in a world with, say, powerful mages, that neither ignored the magic nor made every important character be a mage. For instance. That a character can be interesting and well-rounded and genuinely heroic without having the best powers, or ever attaining the best powers, or even, indeed, ever wanting to. (Mrs. Frisby's children show interest in finding out what happened to the rats, but she doesn't. She's not dissatisfied with her life, and doesn't, I think, see it as the smaller thing.)

tl;dr I love this book too.