The is a root cause and the root cause is someone is unhappy, miserable and bitter.
If someone loves the Yeshiva , Loves doing all the Mitzvoth, Loves the Taasehs AND the Lo Taases they are not leaving.
If you love learning Gemorah, why would you ever stop doing it, but if you cant stand it , are bored with it and remember the Rebbe punishing you because you didnt do something with it, You are going to dislike it
What causes the hate, that is on an individual base.