Because in d1 you didnt need all 6 ppl to know every aspect of the encounter in order to beat it. You could just help ppl through the raid over and over until they caught on. Now you cant even get past the first encounter. Its just 5 ppl sitting there onowing what to do for an hour until the new guy figures it out. Then they are thinking well its going to be about 6 or 7 hours to finish this/ if we even finish it. Why dont we just find someone that already kwtd and we can be done in an hour. See the problem?