The thing I'm having a hard time understanding is why the MCAS finally wins. Did the pilots simply give up? If you feel the aircraft becoming nose heavy, what do you do? You apply counteracting nose up trim. MCAS trims the nose down, and you, in turn, trim nose up. Over and over and over. It should be a draw. (Of course this doesn't take into account the myriad of conflicting and confusing warnings that you are also trying to deal with). It would appear that the issue that eventually lead to both crew's demise was excessive airspeed. Although airspeed is life, in these instances it may have been just the opposite. The higher the airspeed, the more authority the stabilizer has over the elevator until you reach the point where control is impossible. But, if you continue to trim, shouldn't you be able to maintain some semblance of controlled flight? However, when you add in extremely high airspeed, pitch sensitivity becomes a huge issue.