The musician of disordered sound, the poet of decomposed language, the painter and sculptor of the fragmented visual and tactile world: they all portray the break up of the self and, through the rearrangement and reassemble of the fragments, try to create new structures that possess wholeness, perfection, new meaning. –Heinz Kohut
Self-help fails because we are not approaching change in the correct way for our current circumstances and underlying personality. We're not doing what works, and we're not in a place to be able to, have other priorities and/or are not ready to hunker down and sort it out. We may be in a state of constant crisis, for instance, or we may be working on a higher-order problem than we need to be, like working toward a promotion when we don't know if we are on a career path that is a good fit, or trying to get serious in a relationship when we don't even know who the person is.
Sometimes, one leads to the other, though. When we try to push the relationship to the next level, we find out the harder way who the person is, but sometimes when we do that we aren't sure if it was them or if it was the way the relationship developed.
Many times, we're not ready to get the help we want, and we just don't know it. If you learn you are not ready, and you want to get ready, that's great. If you learn you are not ready and you aren't ready to get ready, just have to wait. Sometimes, a degree of self-persecution gets in the way, and that is a downward spiral.
Self-help also fails because the material offered is of poor quality, irrespective of fit.
One of the benefits of failed self-improvement efforts is that we learn we are not ready, and we may learn about what our real needs are. Problem is, a lot of the time people want the punch of the quick insight, the high of the emotionally cathartic explanation, but we aren't necessarily thinking about the long game. We're a short-term culture, by and large, and we pay the price. The upside is that it is entertaining and stimulating, really quite amazing, and often positive, in spite of the frequently shady lining.
The self-help model you pick has to resonate with you. More and more self-development material is selective for particular demographics. This is not just because different approaches are tailored for different problems, but also to appeal to different cultural groups, genders, and so on. This is important because we need to identify with the approach we are using in order to self-motivate. Essentially, we need to form a stable attachment to the self-help material, including if present a particular individual or individuals. If problems are over-emphasized without providing early steps which demonstrate change is possible, a lot of people fall out of the program.
Once the basic hook-in is there, the material has to engage parts of the brain involved with long-term planning and motivation. If that doesn't happen, the person is likely to drop whatever efforts made and wander off, perhaps to the next self-help thing. Reading books alone without following a plan can be inspirational but rarely is more than aspirational.
However, reading self-help blogs can keep the buzz going, and give the reader some variation and novelty to keep curiosity primed. Part of self-help is the reward of how it feels to be working toward a better life, a better personality, a happier place, better loving, better work satisfaction, better health, greater fitness, a longer life, a better me ... a better us. It can be too much, and when it doesn't work, the bitterness is a tough hangover to be nursing. Disappointment and failure make it harder to look for and hope something new will be helpful.
Many times, there is a problem which self-help can't help. That's normal and OK. We like to wait until things get pretty bad, sometimes. Or sometimes we charge at a problem but can't sustain the effort. We need other people to help at this point.
One of the problems with self-help is that it often covers over an over-emphasis on self-reliance. In extreme, self-reliance is not a positive thing, but is a further mask for being unable to relate well with others - trust may be an issue, past betrayals, a very shy interpersonal style, difficulty with communication, ultimately impaired ability to form healthy, stable attachments.
When that happens, and secure attachment becomes a source of anxiety and stress, rather than comfort, we're caught in a catch-22 where what you need for the self-help to work on in the first place is required by the self-help for it to be effective. It seems impossible, almost like a zen koan. The solution is boot-strapping to get out of it, one which can produce profound confusion and a sense of helplessness—much of the time, though, it is boot-strapping involving others that requires not knowing what is going on at first. It's confusing for me just to type it here.
A lot of folks are "counter-dependent," an old psychological term. It's related to "counter-phobic," which is when someone who is very afraid of something, e.g., heights, not only floods themselves to get over the fear, but often goes on to master it (e.g., become a sky-diver, rather than just go sky-diving once). Counter-dependency often extends to relationships, and shows up as help-avoiding and help-rejecting behavior. Many times, people with counter-dependent styles have difficulty communicating, and may seem passive-aggressive and masochistic, or to give a lot of mixed messages about what they want. It can be draining and infuriating for all involved. Point is, if you are counter-dependent you can't get help from anyone else, and you have unrealistic demands about what you want from yourself. It doesn't work.
Self-development is really all about your relationship with yourself, at its core. Because you are not going to an actual other person for help, the way you coach yourself, the way you talk yourself along toward positive change, is key. If you are using pressure and negative criticism more than you can use (if at all) it won't work. If you are too positive or optimistic, you may be cynical and suspicious of your own efforts (perhaps with good reason). It's really easy to be one's own worst enemy, and it can be immediately gratifying. Making use of that aggression, if you want to call it that, so you are working with yourself rather than against yourself, has a lot of traction. A lot of people fail at self-help because they haven't yet learned how to work with themselves. That is step #1. It may also be that we need others in order to be self-sufficient.