These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Joe Christmas may be a Tragic Hero who never could have overcome the burden of being biracial in a racist society, or he could be a raging angry monster who takes out his abusive past on people who do not deserve it.
Lena Grove might be inspirationally faithful or incomprehensibly dense.
Why Would Anyone Take Him Back?: Lena refuses to consider other options for marriage when her child's father leaves her. She remains convinced that one day he will love their child (and her) even after he skips town on her and continually shirks off parental responsibility.
Happy Ending: Although it's not a classic happy ending, there is a little hope—Lena is actively searching for her place in the world rather than constantly running and denying like Joe Christmas. This suggests that maybe her life won't be so tragic, that maybe she'll be able to begin again.