While Walker was unsure what else might be needed to become a dominator dragon, he also understood that there was plenty that the dragons would want to hide. They were all of different elemental affinities. Their paths to getting stronger were their own and required their own focus. If they shared everything, then they might be giving up their weaknesses.
Even worse, it would feel as if they were betraying the past dominator dragons that ahd carved out all of this knowledge to be passed down to them. They had to respect the privacy and the hard work of these ancestors.
"I understand that they would not want to share much with others. Terron was already more quiet and preferred to keep himself to himself. It is a blessing that he is getting along with the dwarves. Especially since we are certain the dwarves want him to help with forging or other mining expeditions." Walker knew that this was just a small blessing though.