Self-help parenting books and blogs caused my spouse years of anguish and disappointment because most declare they've found the one true way. It just so happens to be the least productive and incompatible with many readers' children, bodies, minds, etc.

Many of the authors are selling their narrow experience as if it's divine revelation, often literally because they're religious. The grift usually continues with sponsorships, plugging their other books (or their friends' books), or seminars.

I've read enough about sociology and psychology now that the whole self help industry disgusts me. Receiving such books or recommendations unsolicited strikes me as an insult from folks to naive or lazy to really get to know me first.