Why are humans thought to be good, if...?

Why are humans thought to be socio-sensibly good, if “the fundamental institution of morals into society is to impede many of our natural propensities in order to avert the chaotic unruliness that may arise from them” (QCC, 2002)?

If many people believe that human nature is good willed, then how practical is the belief when we need morals to live among one another? How equal is equality without opportunity, and if opportunity is made avail, how equal is the opportunity to each, if each individual is different? Are humans still savage in so much that we require extra-governed temperance in the fashion of laws, mores, norms, and morals?

I’m starving to understand our animalistic nature and our convergence to being identified as humane creatures of cognition.