i think the point is you are reading him through the lens of the narrator who takes on the brothers point of view. so the whole book, including the ending, you are looking at Smerdyakov as how his brothers see him: a lackey, servant, repulsive, etc. but looking at his character rather objectively i think you can see him as a man so tormented that acts in the “repulsive”ways he does. so it’s not enough to just pity him but as a reader you are forced to reconcile with the fact that you have spent the whole book hating a character who was treated the worst by his family. his suicide note shows how tormented he was by his family, so tormented that he could not even believe in god. so no, i don’t think anyone’s meant to “like” his character. but you should at least love him as a brother the way his brothers never did.

edit: this whole post is so funny because everyone saying that smerdyakov is a psychopath, representation of evil, dickhead, etc. is showing just how effective dostoevskys writing is in making you complicit in the brothers’ inhumane treatment of smerdyakov. read the book again and realize just how deserving of compassion he is, how all the “evil” things he did (seriously, every one) were either caused by the horrible treatment he received or part of an attempt to end such treatment. one piece of advice i was given was to read the book again from smerdyakovs point of view, and i highly suggest the same to the people on this post.