Anyway, great art requires great understanding in order to comprehend. It's fine to read and enjoy the work of HPL on a surface level but disliking it because it makes you uneasy because of his antiquated racism shows that you need to dive deeper. You can enjoy his work and acknowledge his racism at the same time.
I'd like to offer another counter reading of H.P.L.'s racism.
Noting the racism exists, as Ross says, is a weak form of criticism. Further, as Ross also says, the mythos entities form a perfect other. What we all know about mythos entities also is that that they are incomprehensibly more powerful than any human
ever. So let's put this hierarchy into perspective:
Mythos Entity
Superior Race
Inferior Race
Now, I'm all about form equaling meaning, so what meanings can we take away from the hierarchy? On one hand, it forces the reader to recognize how all distinctions based on superior-inferior races are arbitrarily drawn and then justified through pseudoscience. Specifically a pseudoscience that cannot account for the mythos because of how superior mythos entities are to humans. On the other hand, it makes a dire warning about what happens when a member from a supposedly "superior race" finds his or her, but mostly his, self in the position of an inferior. The cognitive disruption caused in such an event literally makes the people of H.P.L.'s work go mad. Such a disruption would make a person, or group of persons, wholly unpredictable.
What I would like to suggest, then, is reading H.P.L.'s inveterate racism (and it is inveterate) as his own psychological struggle with knowing he was no longer part of a favored, superior race and his subsequent fear of what would replace his position in such a hierarchy.