I think you are too focused on the micro choice vs the macro choice. Yes a delay of 500 passengers, but, what else needed a quick fix? How many times have they sold that seat in the next X days? What is the best window to get these fix(es) done?

Clearly the airline said the optimum choice was during this window. Not ideal for you. But, clearly, in the airline's POV, at a macro level, this was the best window.