I find passages in the Qur'an agreeing with your post that individuals are judged by their circumstances.
The Qur'an recognizes a number of ways to earn favor with God, and to receive both divine protection in this life, and rewards in the next life.
One factor would be the education of the individual. But there are many ways to earn favor in God's eyes in the Qur'an, so most individuals should have enough information on Good, to be able to live sufficiently good lives, as recognized by the principles in the Qur'an. Reading the Qur'an, in its entirety, and reading the Peak of Eloquence, intended to explain the Qur'an, the passages referreing to excluding individuals fo other religions from heaven is more an exhortation for Muslims to follow Islam, rather than a realistic condemnation of other peoples.