Hmmm, so Rabbanim have the right to call other Rabbanim apikursim. Who decides who has the last word? Many thought the Rambam himself was an apikorus. They organized massive book-burnings of his works. I guess we should not learn Rambam any more.
Somebody disagrees with Rav Kook, so that makes Rav Kook an apikorus? Let me guess the rule, when one on the right calls one on the left an apikorus, it is true, but when one on the left calls someone on the right an apikorus, it is not.
Note that Reb Aryeh Levine himself was once pushed down into the mud by some kannai, because he associated with Rav Kook.
The Netziv writes that the Bais Hamikdash was destroyed because people went around calling each other an apikorus.
There have always been machloksin about crucial points in the Torah, and Eilu vEilu.
Maybe one day we’ll wake up and realize that the whole purpose of the Torah is menschlachkeit, and nothing more, and that day Moshiach will come.