A student may decide to go to a grad school for a number of reasons (some have been mentioned upthread):
-
The field in which the student wants to pursue a career practically requires it;
-
A professional degree (e.g. MBA) that the student believes may enhance her/his career;
-
The student wants to switch to a different (often adjacent) field;
-
The student is more intellectually curious about a subject matter (e.g. s/he wants to better understand the why’s, not just the how’s). Some schools may have more such students than others.