I'm not nuts about linked brakes either having owned an '04 R1150RT. Why couldn't you just disconnect the brake line that provides the link to the right front brake assembly? Plug the disconnected ports of course.
After being told to go and read the owners manual maybe I should not post anymore. I have been dismissed, after all...
But there is one word in your post - "WHY"
A machine is, by definition (in my mind, at least) something that does the bidding of a person. But now, it seems, our roles are being reversed. Now the machines are so kind as to guide us, and prevent us from going astray...
Never have I come so close to being killed in a car as I was one day when I was in a hurry, and decided to quickly get out into the road. Thing was, there was a little gravel there. One of the wheels slipped on it and Big Brother the Computer cut the engine, making use of the "fly by wire" throttle. Result? I'm dead in the water with a semi truck bearing down on me.
I sold that toyota the very next week. Now I am very careful about what I buy. I look for solid wire to the throttle.
There is no simple, universal rule for braking, or anything else. There are scenarios that require locking the brakes. If the machine refuses, you DIE. Maybe you are about to rear end a semi trailer. In desperation, you choose to lay her down and try to slide under it. The wheels, being giant gyroscopes, will not allow the bike to go over if they are spinning so you lock the rear wheel, using the brake. You get my point?
I'm not the world's maximum notorcycle rider - far, far from it - but I have managed to ride since the 60s without the "help" of any system that negates my control of the machine.