There are two mindsets to hold concerning education and success.
1) A successful education leads to more monetary gain, through being a better educated worker. (Defacto implies that the only reason to get an education is to improve your labor rate, and thus that your only reason to exist is to work for somebody, or to employ people.) Failing to obtain the higher paying job means your education experience was not successful (because the base pay rate is what you are seeking the education FOR, and if you fail to get it, it means you either did not understand the material, or you are just a pathetic loser who cant compete for whatever reason.) This tends to be favored by the corporate elite, and by many conservatives.
2) A Successful education improves your ability to use your mind, in a wide and varied range of applications-- from arranging more symmetrical floral arrangements with better color and texture choices (by being more knowledgeable of what plants are potentially available, knowledge of what humans find psychologically attractive, etc), to designing amazing space ships, and everything in-between, and outside of those two posts. An education exposes you to more information, and exposes you to modes of thinking that better enable you as a person to do *ANYTHING* you set yourself to, and thus, a successful education is one where the person is able to better themselves in whatever way they seek.
The issue mainly comes from taking view #2, then putting it under a burning lens of economic theory, because your whole worldview revolves around economies and cost benefit ratios. Non-economic benefits of a good education are overlooked, because they dont translate into improvements in production, consumption, or distribution, and thus do not contribute to economic activity directly, while having a direct cost associated.
Things like this are telltale of what the priorities and valuation matrices of the people in charge are. A person or group of people who stick to view #1, will want to maximize employment rates, and see education as a means to stimulate economic function. To them, your dear darling child is nothing more than the next new production run of disposable human widgets to install into the economic machine to keep it running. A person or group of people who stick to view #2, will want to maximize your child's total potential, and are unconcerned with how that child makes use of the education, as long as their use of that education brings them some value in their daily lives, it is a successful education. To them, your dear darling child is the next generation of people in society.