AFAICT, this is not only not all that true (teaching adults to code, and the belief that they could be successful, was not a novel when LPTHW was introduced, though some people certainly thought the way Shaw describes; I mean, schools have been taking people without programming backgrounds as CS majors forever, and there have been adult-targeted self-learning introductory resources, books and otherwise, for programming continuously since the 1980s, probably earlier), but LPTHW has not been associated with any substantial change in general attitudes on this point. While it wasn't then and isn't now then general attitude, people still—and AFAICT in roughly similar proportions—buy into the idea of the “from childhood” coder being inherently superior.