From my experience in yeshiva, the guys who spend a lot of time ranting about MO/Zionism weren’t the really chashuve bochurim. The chashuve bochurim were quiet and spend most of their time learning.
It was also the case that the flip outs in the yeshiva world were always more vehement in their tirades against MO than those from yeshivish backgrounds. I agree with GadolHadofi that they are usually insecure and feel the need to show that they fit in by criticizing their where they came from. It always got annoying at a certain point and just became childish.