To borrow a line from recent correspondence, I would like to consider "the attempt to read or evaluate" a person's work. For example, for many, Nietzsche comes across to many as proud and rather depressing, but to get into the details of his writing, one might also see his humble, complex response to science (indicated to me in a comment here). And while it is arguable as to whether there is such a thing as a "popular conception" of a given thinker, what with there being different audiences each with their own criteria as to what constitutes the popular, it would be an exaggeration to say that there is no motion in the mainstream to boil down the image of a person or a time into an intelligible image.
In writing this post, I am thinking particularly of more 'philosophical' works, by which I mean even linguists who attempt to discuss reality, considering that fields such as language and history were drawn into the philosophy of, say, Plato and Aristotle, who considered the significance as well as practical uses of these disciplines. As Pierre Hadot has shown, early schools of philosophy often used what may be described as mottoes in order to assist the everyday man to internalise and apply their philosophical ideas. In this respect, the school of thought would popularise itself, and also keep the higher level of learning away from beginners, often through the use of figurative language with multiple meaning. Such checkpoints are few in modern times: Hegel on his deathbed said that only one student understood him, though misunderstood him.
Adding to obfuscation is the appropriation of thought by various schools who seek to further their own views even to the extent of misrepresenting other views. When I was researching the subject of my MA I found one such book on the same subject that had totally taken my subject out of context. This book is considered an authority on my subject, who knows if or how long that view will remain. In this case, the misunderstanding lay in the fact the different point of departure ravaged the first one like a conquering invader in a war.
This is possible today because though in the dream of liberalism all sides may tell their story, this idealism blinds us to the fact that some groups always want to be victors, and they will do what it takes to discredit or minimalise the other side.
What is more, there are no shared values, we - as a whole - cannot even decide if there is such a thing as a fixed meaning that can be arrived at (I speak generally, overall, not in terms of the exceptions). I know a professor who thinks that meaning cannot be arrived at, yet cherishes his fixed view of certain thinkers, brandishing anyone who does not agree. I find such stands inconsistent, but consider that this type of person is rather prevalent.
Then we return to the average person, beyond the ivory tower. One of the biggest mistakes I ever made was with a friend who I am glad to say still remained my friend after I implied that as she did not expose herself to these thinkers that her thinking was lacking. Isn't that embarassing. Intelligent people who do not read theory may come to the same conclusions as theorists particularly if that those conclusions are useful and meaningful in practical life. (Flannery O'Connor dealt with the preposterous high-mindedness of the university educated in "Good Country People" which effectively shows how education may in fact blind a person instead of assist them in life.)
To write in a non-coherent way, as many modern thinkers do, is to release thought in a way that promotes the free-for-all interpretation. What I mean by this is that myriad (101!) university courses on writing insist on the clear introduction and thesis and full exposition and support of thought including the Ciceronian refutation, yet writers like Benjamin and Nietszche do not write in that manner, their writing reads more like poetry. And poetry in its brevity and empty spaces, its laconicisms, is more mystical, more like the Delphic Oracle, to my mind, because of lack of explicitness. Or where such exists, one is to develop a special technique of reading. Many practical-minded people feel suspicious of this and wonder at the efficacy of something so obscure. Misunderstanding arises. Things fall apart; the centre cannot hold... Where are the maxims to lead the uninitiated into this thought? If the medium is the message, it promises difficulty. My measure here is A. E. Housman's "Application of Thought" and his warning, "Mistakes are therefore made which could not be made if the matter under discussion were any corporeal object, having qualities perceptible to the senses. The human senses have had a much longer history than the human intellect, and have been brought much nearer to perfection: they are far more acute, far less easy to deceive. The difference between an icicle and a red-hot poker is really much slighter than the difference between truth and falsehood or sense and nonsense; yet it is much more immediately noticeable and much more universally noticed, because the body is more sensitive than the mind. " (via) The antidote to fantastic thought he proposes is to "transpose [the idea] into sensuous terms" - which, I might add, is a feature of clear writing: illustrating the meaning of the general and abstract through the specific and concrete (as per lessons taught in writing 101).
So there is something altruistic to some of the attempts to seek the essential in a thinker's work, to extract from it. To demonstrate through pictures. We may speak of morality in this respect because it is a moral responsibility to be accurate if one is re-presenting someone else's ideas.
In many ways, the fate of a thinker rests on whether they have managed to gather a following capable of explaining their worth to others. This is easily seen in the book review given to the unknown or 'unearthed' author.
If a person finds a thinker's work meaningful, it is their job, I think, to apply or to show to others the value of that work. To just say it is valuable and to criticise those who do not share this view I think is not very good use of hard mental work.
That said, there is a very simple useful presentation of a thinker's ideas, as popularised by the Serbian literary critic Jovan Skerlić, who would begin his reviews by praising until his eponymous "but" at which point he would consider a work's flaws. To my mind, this is always the form of an effective attempt to "read or evaluate" a person's work.