For one to alienated from the process of the job/product is for them to experience some negative effects while working. This could be anything from disliking the boss to poor wages to unproduction environment. If one is unhappy with their place/people that they work with then their performance/attitude will suffer.
The same can be said with a student and their education. If a student has low achievement in subjects, made a bad grade on a paper(s)/test(s), or dislikes their teacher(s) and/or peers, what makes you think they are going to put forth the effort in that class. One negative experience could cause that student to disengage completely.