Self –Improvement Books and their authors why they tend to attract many.
For those who pessimistically and condescendingly generalize self improvement books and authors as some random didactic drivels to know that most self improvement authors (other than those with either covert or overt religious ideological agenda) have had some episode of spark or shock which has left them with a very impactful experience.
These sorts of experiences are all the more delightful if they occur to individuals who are also prepared intellectually, psychologically, physically, emotionally to encounter them without any bias or inhibition.
That's why most of them exude confidence, clarity and conviction conveyed through such experience(s).
They are also passionate about sharing their observations, perspectives, perceptions and interpretations of such experiences (which very often tend to make their overall outlook philosophical) by prompting others too to have similar experiences and hence pour out their joy through anecdotal references and incidences, sometimes spicing them with humor, hubris and hyper enthusiasm at having grasped a new dimensions of life.
Often they are so immersed in the joy or impact of the experience that they feel like churning out as much and as often as possible something out of such experiences and its concomitant lessons or realizations.
To the unappreciative and uninterested these may look like over stretching and over repetitive of some theory or truth.
Sometimes certain types of pervasive inspirations result in motivating (at times construed by some as intimidating and preachy by some preconceived opinion carriers- if it is their take away we cannot do anything about them).
At a higher level these sorts of inspiring performances end up in mutual understanding, admiration and encouragement. This is often witnessed in sports, music, arts, science, literary circles etc.
At times even professional jealousy based pungent criticisms carry a subtle undertone of admiration.