One problem with self-help literature, very generally speaking, is that identifying one's shortcomings correctly and addressing them effectively requires, first and foremost, an accurate model of the relevant aspects of one's personality and typically also of the relevant social interactions. Humans, however, are notoriously self-delusional and hypocritical about these matters, and speaking the truth openly and explicitly is often taboo -- even though successful individuals recognize it at some level and adjust their actions accordingly, no matter how much (often honest) outrage they would feel if it were stated explicitly.

Therefore, in order to be palatable to public sensibilities, self-help literature must operate under two crippling constraints. First, it must sugar-coat the problem diagnosis and express it in a way that won't sound cruel, hurtful, and offensive to the relevant audience (and people almost invariably take accurate remarks about their flaws badly). Second, it must frame its solutions in a way that doesn't break the prevailing hypocritical rules about discussing the relevant social norms and social dynamics, or otherwise it will end up too far in the politically incorrect territory for mainstream success.

The best concrete illustration is also the biggest elephant in the room when it comes to discussions of self-help. I have in mind, of course, what is probably the most successful and effective body of self-help expertise ever devised, whose very mention however is guaranteed to arouse passions and provoke denunciations.