Are you the implying that it might have been true then but not now. Just asking from what you posted.
42 years ago Granger was in his late 20s. People evolve. Maybe he swallowed the coolaid at the time, which was poisonous when certain commentary was made about Indians (no different from the Jagdeo era and Africans BTW).
He grew up, and no doubt mellowed with age. The destruction of the Burnham era was evident to all, except for the most hard core. In fact Africans at all levels began to migrate in huge numbers in the post 1973 era.
Prior to that most African migration had been among the middle class. Clearly something changed during that era. Maybe many Africans realized that they were used by the Burnham regime, and were no better regarded than the Indians who they were encouraged to look down on.
Your point is well taken. I reflect on the many ill-advised things I have done in my youth and shake my head.