Or maybe it's the director's fault but she came off as a heartless witch maniac & rigid Christian right wing nut. She had no heart. This movie literally gave me nightmares when I saw it as a kid.
I think I am taking all of this rather well.
In Appalachia during the Great Depression, it was the norm for people to be "Christian right-wing nuts" and to be very strict with their children since they saw alcohol and wayward, fanciful dreams as real dangers that destroyed lives in their poverty stricken communities. So, it was accurate for Neill to portray her that way.
I didn't know that either when I was a kid and found this Mom character kind of scary and angry too . (I thought I would have certainly refused any playdate invites to the Walton house.) I still saw kindness in her - like when she liked the bird's nest that Mary Ellen put on the tree, and felt bad for her worrying about her missing husband. I think Neill did a great job being both an historically accurate mother (and not sugar coating what that was) plus making her character sympathetic and relatable despite all that.