I think I would have enjoyed this more had I read it in the context of a course on colonialism, but, judging by the reviews, that might have led to me enjoying this even less. Conrad has a knack for describing maritime atmospheres - you really feel you are on board of a ship and feeling the waves move you along. Sadly this doesn't translate as well to land and I found these passages to be far less interesting.
To rate this book poorly because of the racism is something that I find a bit odd - while yes, these passages are absolutely awful to read, they do reproduce the narratives and ideas of the colonial regimes at the time. I would assume readers were aware of this and what they might expect within such a story before reading it. While I am in no way an expert on the topic bar a few uni courses on (post-)colonialism (and wouldn't dare fashion myself as someone who has the right to decide over what is and isn't racist!), I did think that the underlying tone of the book is one of critique of imperialism and the horrors brought upon the African continent by colonialism. Nonetheless, the descriptions of Black people in this book are dehumanizing and racist and critique of this depiction is seldom outright declared within the story - this should not be downplayed and is, in my opinion, a valid point of critique with regards to this book's fame.
At the end of the day, I'd much prefer to read a book about this time period and topic that isn't from the perspective and pen of an oppressor. Also, I think I'll stick to Conrad's maritime writings.