Lefty loosy, Righty tighty. Right? But...

[02GF74]

That's a very bad idea. Even if you've only got one hand you are better off with two brake levers.
With front and rear brakes worked off one lever, you will be unable to brake very hard without locking the back wheel unless the back brake is set so loose as to be no use.

yes but if you were to have such a system, you would design it so that the braking effort is mostly on the front, for the reason you stated.

Similar to car braking systems were the bias is at the fornt since one pedal operates brakes on a 4 wheels.