"Official," is not a synonym for, "good thing to have in a notable bit of culture." Is "WotC said it officially, so it is okay, really," only works if WOtC is considered a moral authority. Much as we might prefer to dismiss it all as "they are fictional, so they don't matter," that argument kind of falls apart - by that logic, any fiction depicting racism, or abuse, is okay because "the characters aren't real, and it isn't the real world."
Stories are not "just stories". They are also one of the tools we use to propagate our cultural ideas. So, it pays to at least consider that aspect of the issue.
I do think the idea that alignment and culture is just the default should be more front and center. There could also be more discussion of how different campaigns handle it, although there is the simple reality of page count.
But there have been many, many studies not just of D&D but video games and other popular culture. There is no causal events between violence in games to real world violence. Studies have shown that D&D encourages social skills and problem solving.
I just don't think that a game that reaches a tiny fraction of the population is going to have any real impact. Discuss it? Sure. Get rid of default alignment and all aspects of a default culture ... I think that would be too far.