I believe the following stylized facts are roughly correct.
1. American K-12 students perform in a mediocre fashion on international standardized tests, and other data likewise suggest that the academic performance of American students is disappointingly modest.
2. Following from the first point, poor K-12 academic preparation is a significant reason why colleges need remedial education programs, and why they have high drop-out rates.
3. Great teaching leads to better results than mediocre teaching.
4. Most K-12 teachers have studied extensively in colleges of education.
5. Teachers who do not come from a college of education background do as least as well, and often better, than those with certification gained by taking education college courses. Programs relying on non-education-college-trained personnel like Teach for America are highly successful.
6. Standards in American colleges of education are appallingly low, and a sort of anti-knowledge, anti-intellectualism is often apparent. Typically, education students have below-average indicators of college performance (e.g., relatively low high school grades and test scores), yet tend to receive extremely high grades in their education courses. averaging A- or even higher. Research done at the center I direct (the Center for College Affordability & Productivity), took a sample of 174 public institutions with education schools and obtained grade data from campusbuddy.com. Looking at over 1.3 million grades, we found that the average GPA in education classes was 3.65, and 76 percent of students received an A- or better. Contrast that to university-wide GPAs that averaged 2.99, with 41 percent receiving A grades. (I have talked about the wider problem of university-wide grade inflation here and here).
7. The colleges of education have often fought genuine education reform that rewards teachers on the basis of student learning. They have fought to keep certification rules requiring students to take many education courses. Too often, they seem to believe that the maximization of student self-esteem is more important than the acquisition of knowledge.
To be sure, not all colleges of education fit this model, and there are some effective education professors teaching at some schools. By and large, however, colleges of education are considered vast wastelands of mediocrity at most comprehensive universities. And it certainly seems that most of the good research on learning, educational costs, etc., is being done outside education schools by psychologists, political scientists and economists.
Thus it seems to me it is a dubious proposition that undergraduate colleges of education make any sense at all. I am not, of course, suggesting that it is not worthwhile studying the process of learning, and trying to improve it. To the contrary, we do too little, not too much, research into what works in terms of improving student educational outcomes. But future teachers are better served by getting good grounding in academic subject matter, augmented by some practice in teaching under the guidance of an experienced mentor. Courses in the history of education, for example, are less useful to the future math teacher at the intermediate or secondary level than a course in advanced calculus.State governments should consider defunding students in colleges of education, requiring future teachers to major in an academic subject, etc. There should be upper limits on the amount of work in pedagogy allowed in a bachelor's program, and requiring teachers to get a master's degree in education (a way educrats might use to preserve the education schools) likely should also be prohibited. Most top-flight schools already do not have undergraduate education schools, but this blight on true "higher education" should be discouraged at all institutions depending on taxpayer funds.