Ray Franz, in Crisis of Conscience, explained the process in which GB members would raise issues. Some were discussed at length, others were given a cursory discussion and then they'd pass on without deciding anything. He explained how the GB was led by some fairly forceful individuals (many of whom have since died) and certain pliant GB members would always vote to support them. By his account, issues that were raised that suggested a softening of attitude (ie, a move away from hardline doctrines) were quickly dismissed or ignored. Some of those were issues he raised, and he held the view that they were ignored because it was he who was raising them.
Things may have changed since then, of course, but don't forget that new members of the GB are chosen by existing members, who would always take the high road and ensure that no one could suggest that they were compromising or allowing the rank and file to go soft by appointing liberal or intellectual members. There is therefore a powerful mechanism in place to ensure attitudes never change (and "newbies" and "wannabies" would always be trying to impress others about how "uncompromising" they are!)
It is unfortunately part of the mystery of the upper echelons that rank and file Witnesses are kept in the dark about how decisions are made. It's an attitude that permeates every level of the hierarchy, including bodies of elders within congregations, which keep a conspiratorial code of silence about decisions, with information released on a need-to-know basis only.