"Are you surprised by this? Do not be. Remember what you know about this class of ultimate soldiers and warriors. Each god pilot must become strong enough to stand on their own, or else they will not possess the resolve that is required for them to become god pilots in the first place."
This was simple enough to understand. God pilots must possess complete confidence in their own strength and ability to overcome all of their challenges on their own. Aside from leveraging the strength of their mechs, they must strengthen their willpower to the point where they could solely rely on its reality-warping effects to defeat the toughest opponents!
Any reliance on outside help made it a lot harder for god pilots to complete this necessary mental evolution.
In that sense, Patriarch Reginald Cross actually adopted the right approach in advance. His purity and insistence on relying more on himself would help increase his chances of advancing in the far future.