Our speaker is relatively cool and understated, considering the subject matter he's talking about. (And we're just assuming it's a "he" here, since we have no evidence to the contrary.) He's not getting angry or yelling about social injustices. Instead he has a more objective perspective, which also happens to be one of Dunbar's calling card qualities. (Check out "Calling Card" for more on that.)
So the speaker has a universal sort of voice that's not exclusively limited to any one person or people. He kind of takes a step back and gives us a fuller perspective of what's really going on with all these lies and hypocrisies. In doing so, he seems to suggest that this is not the sort of problem that's limited to any one culture, or person, or time.
Instead, this detached approach helps us to consider how masks are all over the place, that sometimes they're also a matter of survival in cultures where may react violently to people speaking honestly about social problems. Perhaps this is also why Dunbar's poem is still widely read today. Thanks to our detached speaker, it can be applied to all sorts of social circumstances and places.