because raids do not repeat...... that is the answer. you have to think deeply about the money and how to make money. you have to understand what is power creep and why it is important to this game, and why raid FLB is bad for power creep.
it simplest terms: think about 2 scenarios, one with FLB raid and one without and think 2 steps further about the possible outcomes and outcomes of the outcomes and the outcomes of the out comes of the outcomes. and you will see raid FLB is inferior revenue.