No. In the book, it was obvious he truly wanted to get to GM level. He had all the advantages most kids don't have. Also many GMs didn't have. World class coaches from age six, supportive parents, etc. If he could have made it, he would have.
So, your thesis is that he didn't have 20 more rating points in him even if he invested a decade of effort?
I read his book "Attacking Chess" (1995) that he wrote soon after becoming an IM, and it was obvious he had high hopes of getting to GM level. He studied, and played for some years after the book was written. If he had had the talent to get to GM level, he would have. He eventually realized he didn't have the talent to get to GM level, so he "lost the love" as he put it.
He last played seriously at about age 24 and his high FIDE was 2480.
Considering that GM level is 2500, and his relative youth, don't you think it's unfair to say that he didn't have the talent to get to GM level?
No. In the book, it was obvious he truly wanted to get to GM level. He had all the advantages most kids don't have. Also many GMs didn't have. World class coaches from age six, supportive parents, etc. If he could have made it, he would have.