Because performance means more than just one second less in 0-60 times. I don't agree that for the rest of the "auto industry" the difference between a performance model and a standard model would be $24k and a software flag or even a motor swap. Generally for cars that are intended for any kind of performance driving, upgraded brakes and suspension are normal. Better tires, more supportive seats -- these are pretty typical also. I can assure you I am not interested in cosmetics, in fact for some brands the true performance models come with less bling, not more.
My disappointment is that the 3 -- at an $80k - $90k price point -- could be a fantastic car. From what I have seen and heard though -- I don't own a 3 -- simply increasing the power will not transform it. Yes it will give it 0-60 bragging rights, but that's all.
I get it -- most here do not care about any of this and just want to get the car ordered, or perhaps they feel that these things will reveal themselves over time. I'm not cancelling my reservation, but I won't order the P or any other 3 if the spoiler is the only delta.