Yeah that's what I was thinking. I've done a lot of work on my truck (Nissan Titan) and all of my thought process for my bike stems from that. For the truck we roughly estimate that 10 pounds weight reduction is about 1hp gain so losing that much weight off the bike seems like a great trade for a 3hp loss that is easily recouped from other mods.
I'm not an engineer but I have spoken to some engineers...weight reduction isn't that simple.
The best part to remove the weight is moving components. Wheels, tires, brake rotors, drive shaft, differential, etc.
Some engineers say removing 1 lb off wheel could equal to 15 lb weight saving, although it is case by case.
If you don't understand, think about you carrying a 10 lb backpack and start walking. Not much of difference isn't it?
But think about walking with 10 lb shoes. Which is your moving component, I bet you would take a lot of effort and even slows you down quite a bit.
This is why people get drastically bad result when they get 22 inch rim on their Mustang and stuff because they're so heavy.
I've read an article written by BMW engineer as well.
As you may know BMW uses V6 for modern 3 series, not Inline-6. When they switched to V6, a lot of BMW fans rant about it.
But BMW engineer said going from Inline-6 to V6 gave them instant 20%(or something?) more horsepower because of significant weight saving on crank shaft.
V6 configuration will allowed lightweight and short crankshaft, where as Inline-6 needed much longer and heavier crankshaft.
They kept piston, rod, valve, etc...everything the same and made it V6, the power difference was so drastic that they simply had to ditch their Inline-6 tradition.