Why Philosophy is not useful to most people
Firstly, I will say that as a goal, Philosophy tends towards the goal of Eudaimonia. That is, the everlasting, growing, blooming happiness that stays and can be nurtured throughout a life... through the life well-lived. Accomplishing this, many divisions and many camps and tribes form and batter their drums to this goal... but most end as noise and little else to that goal. As I see it, Philosophy falls into 5 main camps(in order of least useful to most):
Obvious
So the obvious philosophy, is just... obvious. Sometimes it can be forgotten, or ignored so reexamining it is occasionally useful... but if you're not stupid, this philosophy will not be useful to you. You'll ring these ideas, and find you hear nothing, as they are nothing.
Wrong
Next is philosophy that is plain wrong. This can happen in many ways. Logical sleight of hand in Dialectics(What sets up Hegels school of thought, as well as the groundwork for Naziism and Communism, in particular each of their manifestos), or often enough through fallacies. While even if it's wrong, it may serve to be useful to the person- so it's not enough to discard it entirely, but if you're critical you'll observe these errors and through judicious use of the Socratic method and careful questioning... you'll dig and find these ideas ring hollow.
Clever
Here lies long treatises and long tracts of text on some point or other with little application. One such example is discussion with regards to Kurt Gödel's incompleteness theorem which shows the incompleteness of axiomatic systems where there can be unprovably true or false statements, which provides an incomplete mathematical or logical system(the same for all axiomatic systems). Now if that doesn't sound useful to you, it's because for the most part it simply is not useful to you unless you dig into the minute details.
Additionally philology and semantic arguments follow from here. They may present a case that is very clever, smart and ultimately... do not add much to anyone's life. You will ring the idea, and find it makes an interesting and fanciful noise. A mystery that adds little to your life.
Metaphysical
Now we get to the realm of Kant, the realm of Jesus Christ, the realm of Theology and Pascal's wager and Plato's forms. They presuppose some quality beyond observation and sense and quite often align goodness or evil to these presuppositions- or create abstract concepts with no foundational reality to them such as sin. The primary issue with these is Pascal's wager applies infinitely to all possible belief systems, all possible faiths and all possible punishments, and as a result you have no logical game-theory-made foundation to establish a belief. Hume's guillotine comes into play too, as you can observe many facts such as "people can kill people", "murder happens", but until you present a moral fact such as "murder is evil" the guillotine does not fall. You cannot derive good or evil actions until the guillotine falls, but that requires the existence of a moral fact.
In the words of Stirner, they are phantasms of the mind. Perhaps useful to be aware of as others do genuinely believe in them with the fullness of their heart, but phantasms... spooks... all the same. These ideas, you ring, and all you hear is the knell and the Ghost.
Psychological
Lastly, we come to perhaps the most useful element of philosophy, which is reasoning about psychology. Of course, all of this comes second to *actual* psychological experiments and experimental evidence, but lacking that, it provides the best and most useful tools to accomplish this Eudaimonia. Tools for improving your health, your power, your expression, your creations, your views upon the world and the mind, and why all the previous forms of Philosophy trap people in the mirror realm. That said, even among Psychology, it can still enough be a glass palace... fancy words and a fancy palace of purest and untested glass.
The idea rung... The psyche collapses if the wisdom is not earned. It is in here that the proto-psychology of Carl Jung and Friedrich Nietzsche are most useful... but even then I find their answers lie at the heart of one action and that is creation. Creation is a satisfied expression of the person. Weak people cannot create as they cannot express in the form of power or violence. Loveless people cannot express in romance. Mentally ill people cannot express in the form of normalcy-- and here you have the importance of experience, novelty, an open-mind and the knife's edge of life. This capacity to expression is the capacity to creation, and the importance of power-- this fullness of experience is the peak of Maslow's Hierarchy of needs.
The blossoming tree of Eudaimonia, born out of roots entrenched in hell- half burnt, half scorched, half suffering. Born out of a canopy reaching to the firmament, the cosmos, the heavens- offering shade to all the creatures of the earth and all the wisdom within... and from its branches grows fruit. Creation.
If you enjoyed this post, I will point you towards my short pamphlet, Liber Vitae Affirmationis, as it expands upon my own personal view of the Psychological element of people.
=> You can read the preview, where the first chapter goes into much more detail attacking cleverness and metaphysics in a different way.