In my opinion, the whole "pressure in Boston" situation is overblown. What did Nomar in was the wrist and the fan negativity, which is different than pressure. Pressure is a need to perform. Negativity is fans screaming at you, calling you selfish, and wishing you out of town.
If it really had been the pressure in Boston, and if it really is bad for young players, how did Nomar manage to hit above .320 from '98-'00? It makes no sense to say that the pressure got to him after he won two batting titles. If anything he should have improved. I agree with you that he didn't fully develop with the sox, but lets not try to shift the blame to the pressure of playing in Boston.