The one answer for the four questions on Tisha B'av

The one answer for the four questions on Tisha B'av WHOSE FAULT WAS IT? The Bais Hamikdash was destroyed because of Kamtza and Bar Kamtza. (Gittin 55b) 1) Why was קמצא at fault? (He didn't do anything) 2) Why wasn’t the בעל הסעודה at fault? Shouldn’t he be the number one culprit? 3) Why were the רבנן who kept quiet at the meal, not at fault? 4) The Gemoro on 56a said it was ר' זכרי' בן אבקולס fault. Everyone involved in the מחלוקת is at fault When the Gemoro says "because of Kamtza & Bar Kamtza the Bais Hamikdash was destroyed", The Gemoro doesn't blame these two people. The Gemoro says because of the story of Kamtza & Bar Kamtza,  the Bais Hamikdash was destroyed. In the story, there are, many whom we can blame. 1) Bar Kamtza, 2) Ba'al Haseudah, 3) Rabonon and even 4) Kamtza* *The Ben Ish Chai writes "Kamtza which means Grasshopper was a code name for R. Zecharya ben Avkulas" אמבצי