This, I think, is because of a rather obvious factor that she's at pains to ignore. You see, when speaking to a mass audience, she isn't permitted to use any of the rhetorical techniques she uses to give her confidence when speaking to her family. She isn't allowed to bellow in rage, she isn't allowed to make that stupid palms-out pleading gesture and accuse the audience of hating her, she isn't allowed to whine piteously about how cruel they're being and how they want to destroy her, she isn't allowed to threaten them with disproportionate violence and she isn't allowed to throw things at them. Since she's limited by having to act like a calm, rational human being instead of the raging asshole she actually is, she's more or less been declawed and thus is incapable of expressing herself creatively.
Since she isn't really aware that she's got a wicked temper because she probably blacks out on when she goes berserk, she doesn't realize this about herself but instead ruefully comments that maybe if she had been more forceful with her children, they might actually have listened to what she said.