Your argument is right. But the question has been raised by a PCC student who had advantage of practical training.
In professional examinations; if you wish to score high; then definitely some knowledge about each subject is a must. This must be understood well when a student joins CA course.
In most of the cases; students and their parents never take this pain despite knowing the fact that CA is the toughest course. The students should know at the time of joining CA what is full syllabus of the course.
The tendency of not referring the whole syllabus is due to past habit till graduation which never works in professional examinations. Those who mould themselves according to the professional requirements; get through (although they were average till graduation) and most brilliant students who scored high marks till past; fail in CA.
Many students would argue after joining the course that how we could know all about that ?
I say, it is not impossible. How many firms you have visited before choosing this course ? In most of the cases; the course is chosen on the advice of students pursuing CA.
Ask a CA final student what he will do after passing CA ? And I am sure; more than 90% students would be unable to tell clearly what they will do after CA qualification.