I share this view. When I appear to forfeit some utility in favor of someone else, it's because I'm actually maximizing my own utility by deriving some from the knowledge that I'm improving the utility of other agents.

Other agents's utility functions and values are not directly valued, at least not among humans. Some (most?) of us just do indirectly value improving the value and utility of other agents, either as an instrumental step or a terminal value. Because of this, I believe most people who have/profess the belief of an "innate goodness of humanity" are mind-projecting their own value-of-others'-utility.

Whether this is a true value actually shared by all humans is unknown to me. It is possible that those who appear not to have this value are simply broken in some temporal, environment-based manner. It's also possible that this is a purely environment-learned value that becomes "terminal" in the process of being trained into the brain's reward centers due to its instrumental value in many situations.