My game has a tiefling PC, a paladin of the Raven Queen. He deals death to anyone who asks for it (and plenty who don't), broods on the fate of his dead people and their civilisation, and gets on well with duergar (although suspects that they haven't fully internalised the consequences of their own people's dealing with devils).
In a word? No. Assuming the default background for those races that stuff happened literally thousands of years ago. Current members of either race's only connection to it would be family stories and extremely old books. Ones which would likely have been replaced in common tellings by much more recent, important happenings.
Much like Americans descended from English people, who happened to have ancestors who fought in the civil war dont talk about the war of the roses, or the hundreds years war. And they dont really talk about the civil war either. They talk about Iraq, or Vietnam, very occasionally WW2.
Actually a more accurate comparison of the length of time involved would be a bunch of southerners sitting around obsessing over the Roman occupation of Britain. And how much they have in common with all the english over it.
My post was attempting to illuminate how Tieflings and Duergar share a unique (to all the races) biological and cultural history; their infernal bloodlines and fiendish pacts. With this comes irrevocable stigma from the greater world culture. Given that
their infernal heritage is visible as well as intangible (through culture and history), no manner of years will undo this stigma, not 200 nor 2000 nor 10000 (unless it is bred out or a recessive trait miracle mutates it out over generations...but seeing as that hasn't happened in 10000 years and we're still talking about Tiefling and Duergar...I'm pretty sure we need not worry about comparing 2000 year old societies to them...age is irrelevant.).
Along the way, Tiefling society and culture collapsed under the weight of its own corruption and its remnants scattered to the wind, some ashamed, some embittered, some just disenfranchised...but with no focused ethos.
vs
Meanwhile, the Duergar culture ossified further and deeper until it became the perfect example of a proud, militant society, steadfastly and unashamedly devoted to rigid veneration of the most evil and powerful of devils - Asmodeus himself.
A Confederate loyalist's descendents, conflicted over the family's past but unable to escape the reality of that history...and the inescapable notoriety and stigma it carries.
vs
A Confederate loyalist's descendents, unabashedly anti-Yankee Nation to this day, flying the Army of Northern Virgina's flag proudly in their front yard, still representing that ethos and willing to give the what-for to anyone who looks at them cross-eyed.
It doesn't matter what people "talk about" or "how long ago stuff occurred". I'm not sure why you brought that about. We were talking about shared history and how that shared history does, or does not (your position, provide insight into the other party exclusive to those that share that history. You said that Tieflings and Duergar wouldn't possess unique insight into the internal goings-ons of each members' race. You said that pemerton's character could have been a human and it would have worked just as well. As such, your position was disputing both our contentions (that it was a thematic choice) and could only be a "munchkin choice" for "kewl powerz", as you put it. I dispute that and attempted to display my reasoning; They share infernal bloodlines, a cultural history of fiendish pacts, and
visible, physical marking from their fiendish heritage which indelibly marks them and brings stigma from the greater culture...and with it the natural kinship possessed by a universally maligned people (justly or unjustly).
You then went somewhere else with this last post. Of which I can't make heads or tails of.