In my opinion I think it is inherent to man to "want to please God". I could go a step further and say some believe that this is a "guilt" that was put into us at the fall of man.
When a child gets in trouble, they do what they can to get back into their parents' favor.
What this means is like you said. Because we want to be right with God, we want to know exactly what that means. We want to know what the right way to please God is.
Also, just like you said, the devote, religious argued over this and began killing those who didn't meet their criteria for providing the right blue.
This is the second reason that Jesus came. To correct the Pharisees and religious rulers. He pretty much tells them "Look...The Blue is no longer an issue. I am going to give God the best possible blue FOR YOU. The most important thing is to love God the father and love each other."
But to this day there are still religious people who argue over the best blue. I believe their intentions are good, but rhetorical.
Again, I will probably get destroyed for this, but I think Jesus provided the moral standard before he left of "Love God and Love your neighbor. All other things hang on these." Religious people are welcome to rhetorically argue these things, but once it leaves "Love God and love your neighbor", it becomes a problem and I completely agree with you. It is no longer a moral compass if it causes conflict and the fruits of the spirit (peace) are not there.
I have learned to stop arguing and stop trying to find out what the best blue is. I have learned to just accept the two rules that Jesus laid out. It eliminates the arguing and the concern.