Mr Wonka is actually stalling simply because sometimes children haven't learned their lessons. And that there is no easy way to teach children to learn their lessons they always learn to learn their lessons the hard way. Through the teaching method of tough love. sometimes children can't always get whatever it is that they want Kevin cuz they wanted and wanted so bad. Come to think of it children live by a saying "if you want something you have to get it yourself" Especially when the loved one is trying for the child trying hard for the child. But the loved one is not to let the child get the upper hand or have power over them. And sometimes not only the child get their way children often or not always have to learn the hard way.
Just remember it the novel, it wrote about Veruca struggling while everyone watched her get thrown. "Veruca kicked and screamed, but it was no use. The tiny strong paws held her tightly and she couldn't escape."
