i've been at this RC thing for about 7 years. in that time i can't count the number of different motors i've had in countless different RC's. i literally have never had a sensor board go bad before this. by your own admission, the monster max motors have the rotors shimmed too close to the sensor board. shouldn't be much more to say about it. and yes, when i put the new sensor board in, i shimmed the rotor .2 further away from the board and so far so issues.
you must be in a couple pichers of trinity kool aide deep to start attacking my driving skill. whatever caused the sensor board to fail, it was nothing spectacular as i don't even remember the crash that caused it (if that's what indeed caused it). nothing else on the buggy broke.
i don't consider a motor sensor board to be a consumable item. servo gears? sure. i've stripped some out. nothing lasts forever. i do expect a motor to last longer than 3 or 4 race days and i expect them to be built properly so as to prevent them from breaking.
don't cry about it bill. me not buying trinity products won't keep a dollar out of your wallet.