Renowned writers, by default, are treated with respect for their thinking and their writing by default. There is undeniably a degree of status placing import on writings by a big name in literature and that status lasts. Chinua Achebe seeks to take aim at Joseph Conrad and his Heart of Darkness, making note of the unbounded racism found within.
It is well known that it is easier to follow or ignore an immoral crowd than it is to refute it. The innate racism that was commonplace during the publication of Heart of Darkness was what allowed the racism facet to not have affected its literary merit, which probably is not an excuse for slandering any portion of the human population. For now, I will refrain from further judgement on this basis as I have not read it.
However, the contents of the essay hold dark implications that accepted works (or really anything thay cna convey ideas) can easily be hiding in our everyday lives that share a message that is more conducive of evil than of the well being of humanity. If even something as tough as the literary community has had trouble calling out a novel for its blatant racism, how many other seemingly benign outlets of information convey a harmful message?