I've not seen any reports of motors failing after their expected service life, so not sure how you can say they will fail prematurely.
These motors are essentially stepper motors with a fine angular movement. When they are stationary (even if they are bearing a load) there is no movement, no friction, no degradation. Essentially it's just a stationary electro magnet.
As long as there is a supply of power, the coils will remain energised and will perform. Only if they overheat and melt would they stop working. I check the temperatures of all motors after each use (good practice for any motors) and the gimbal ones are the same after a flight with a heavy HeroHD and the lighter GoPro3.
Yes I accept it wont help the gimball, but i have seen no evidence of any negative effect yet. If in a few years it fails, no doubt you will all jump in to say "haha told you so" but there are stories out there of gimballs breaking for a whole variety of other reasons more common. If it lasts a few years, only cost me £150 and served it's purpose then i have no issues with that.