I will IY”H explain the super-rationalist position on the “power of Gedolim”. Many things in Judaism are reactionary. We see throughout history that Minhagim and G’zeiros came around as reactions to issues affecting Judaism. Most recently, the Kollel lifestyle was a reaction necessary to save Torah learning post-WWII and before that the Mussar and Chassidic movements were reactions to the Haskala.
A lot of the super-rationalists see places where Chassidus influenced or changed standard Jewish thought and are attempting to go even more rational than Jewish thought was in the first place to counter that. The concepts of “Daas Torah” and “Emunas Chachamim”, which are now spoken of as Ikkarei Emunah by some here, just didn’t exist in even close to the same manner (if at all) 500 years ago. People always went to a Rav or Rosh Yeshivah for advice, but they never treated their words (nor did the Rav himself treat his words) as Halachos L’moshe Misinai. It is very clear that Jewish thought in this area has been influenced by Chassidism (I wonder if a Bar Ilan search would even show up the phrases “Daas Torah” and “Emunas Chachamim” if you went Rishonim and earlier) and some are reacting to the extreme to that to try and say that that is not part of what they feel is authentic Judaism.