You really have no idea how lucky you are do you?
Guilds had as many as ALL their good raiders leave during the 5 month wait. My guild lost 4/8 waiting for HM TfB. And you complain about 1/8? Take a look around, you're one of the lucky ones buddy.
I was talking about my own raid group. other raid groups in my guild lost people in the time between ec and tfb as well. some lost 1 or 2 peeps as well. one group folded entirely.