I have heard many people in academics state that a thesis is a students own project and that only the student is responsible for its quality and completion. Unfortunatelythis does not agree with my own observations. I see many supervisors who have very specific demands but take very little responsibility for the consequences of these demands. For example some supervisors demand that the subject of the thesis is in a very small area of research closely related to his own work, even if the student prefers a slightly different subject. Or have very specific requirements for a subject on other non-academic grounds. Switching supervisors can delay the progress of the student significantly. In this case the supervisor severly limits the possibilities of a student. However when this leads to problems with selecting a subject the supervisor does not grant any leniency in terms of deadlines. Isn't it then appropriate that the supervisor helps more with topic selection/ assumes more responsibilities in issues related to this particular demand? For example the supervisor could be more tolerant on allowing a student to continue work with a new topic if the one the student suggested is not feasible.
This leads to two specific questions:
What kind of demands are reasonable for a supervisor to have, particularly regarding scope and topic?
What kind of responsibility does the supervisor bear for the consequences of those demands?
This question is about master and bachelor theses. I am not sure if it matters but my university is in western europe. My personal opinion is that saying that the student is one hundred percent responsible is a facile argument, since as soon as a supervisor has demands that are not solely to the benefit of the academic value of the thesis, or normal order of business , he should at least take some responibility. However I am very much on the fence about to what extent a supervisor should facilitate their students in this type of situations. If the issue remains unclear I can add specific examples but I want to avoid discussing issues particular to a student, university or even field.