Why? Aside the fact that the history and political climate means Kossiths are not only distrusted, but them gaining a position of such pwoer and influence as a Inquisitor would NOT go well.
Immagine a ex-natzi leading an army loyal to him to "free" france from its' civil war. That would go over soooo well.
And IIRC; a Kossith wasn't even supposed to be a playabale race initially. That would mena this feature was tacked on due to popular demand. And tacked-on features in general tend to suck.
To put it simply, a "one size fits all" approach just doesn't cut it when the races are so different. Each race would practicly need it's own game.
People and ideologies are not the same thing.
You can be an ex-nazi, but not an ex-german. The Qunari Inquisitor will be unaffiliated with the Qun. I theorize we'll have a superman kind of deal, where he/she was raised by another race.
Also, apparently the Dwarf Inquisitor is from House Cadash.