The kids need to get better, and that's what Zecht has done when he went on his own.I just read past that, and while Shizuko and the other moms are a bit harsh....I think they are still right.
Maybe you can say the moms didn't educate their daughters, but I think as far as their actions are concerned, they have to take some responsibility for it. When they went from adventurers to wives themselves, they didn't lean on anyone to learn how to become good wives. They also took care of everything themselves when they were their own party.
So they expect a certain degree of independence and initiative from their girls, that's what they taught them really. Unfortunately, they chose to exercise that by ditching Ceres. All the stuff he did for the party honestly isn't that hard, or else are skills they should have been interested in learning themselves. They got really lazy, and that's what the moms can't abide. Hard to say if that was the mother's fault....to me, it's a weird mashup of their culture regarding marrying young and the influence of their parents.
As for Zect....well it's true he's still the hero and more capable in Ceres in many ways, but it's not really about that, is it? The moms didn't marry Ceres because he was the Hero or could fight well. And that should never have been a reason for Zect's party to ditch him. Of course it doesn't matter to his mother. If anything, she has the clearest perspective on it because she's an independent woman who is perfectly capable on her own AND stronger than her son, only she chose to be 'ordinary'. Her son's achievements aren't impressive to her to the extent they can be used to excuse his behavior.
My only comment for the actual chapter though....she kicked him off a cliff? Lida....
But after the girls came back to Ceres, he once again started to take care of the girls for about everything. Are we really expecting for the girls to improve if no one takes the time to teach them ? The mothers reproach the daughters not being able to cook and do chores, but once they're back home, they're still not doing their job as mothers (which is not to do everything for your kid, but to prepare your kid to become an adult).
As much as the MILFs are great wives to Ceres, they are terrible mothers to their children. It wouldn't have required much to make the mothers more likable. Instead of the chapters where they make fun of the girls and show off how superior they are, have a few chapters about the mothers spending time with their daughters with interactions like "Let me show you how to do your hair." "Let me teach you how to cook your favorite meal." etc... Have a few wholesome moments between mothers and daughters instead of the girls constantly being punching bags.
And when Zecht comes back with the girl he saved from slavery, have at least his own mother who suffered the same thing acknowledge the good her son has done. I would have loved to read a discussion between Shizuko and Luna to show Shizuko the kind of man Zecht has become... But no, she slaps him in the face because he didn't force three girls who didn't love him to stay in his harem...