In developed and emerging countries, education is one of the key supports of their societies. A great number of politicians make promises about increasing the quality of the educational institutions. But should a equal national curriculum through college be part of these promises. In my point of view, yes. And we should why, and go further in this question.
First of all, in a nation where students have the same national curriculum, there is a better transition between the different levels of education. It's easier for a professor, let's say of middle school, to organize its classes knowing that every student has the same core of knowledge, while if students had a different curriculium prior to middle school (to keep using this example), professors would be teaching topics that some students with a certain education background would be prepared to, while other would have a lot of problems understand. Let's take the extreme example of Sciences. A student that was schooled in a fundamentalist christian school, which teaches creationism, will have more trouble understanding natural evolution than a student which learned the principles of science in a non-religious school. A equal national curriculum would solve this problem of overlapping of different views about a certain topic (we are not interested in discussing which view is better, only in proving that a uniform curriculum is more advantageous than having different schools teaching with opposite views the same topics).
Secondly, an uniform curriculum is the more efficient way of evaluating the effort and performance of different teachers and different students. The same national curriculum allows the existence of national exams, which is a proven method of ranking schools. These national exams are also a very efficient way of universities to choose students between the pool of candidates. Without an equal curriculum, students would be teached different topics in the different courses, which would unable an unbiased evaluation of schools, students and teachers, because even if 2 classes of students has the same academic results, we couldn't compare them, because the were being evaluated in a different way.
Finally, a unique national curriculum decreases the variance of the quality of schools across the country, which is one of the main creators of income inequality in society. A nation where schools have different curriculums, the less funded schools will, on average, have the less demanding curriculums, increasing even more the gap in the education of the different social classes. So, a country should use an equal national curriculum as a way of giving a more fair opportunity to its citizens. Look at the examples of the northern europe countries. Countries like Sweden and Norway are some of the countries with the lowest Gini Index in the world. This success is not only fruit of a progresssive tax system, but also because of an education system, with a uniform national curriculum, where schools have a very similar level of ecuation across the country.
Therefore, even if an equal national curriculum could prevent schools from implementing more demanding curriculums if they wish, overall for the country, this is the best way of achieving an efficient educational system, where students can end their academic paths, being prepared for the demanding world of work.