Honestly, he looked just like a weird human. This way they give off more of an exotic vibe.
And by the way, they haven't re-designed them per se. From http://dragonage.wikia.com/wiki/Qunari:
Yes, that's just a story to sell the re-design, but there you have it. :shrug:
It's a sloppy retcon if you ask me. And a nonsensical one. The Qunari's horns are too large and thick and they have prominent bone ridges where they grow to ever be able to make a clean, scarless/stumpless cut that all those Tal-Vashoth were supposedly able to do in DAO. I think I can come up with a better one. Ahem...
"Like all races of Thedas, the Qunari are a diverse people of several distinct ethnicities. Though in the past, the horned ones were widely believed to be an entirely different people, in truth, the presence, shape, and size of the horns is no different than the assorted hair colors you, I, and our neighbors possess. The hornless variety, more common in Seheron, are the ones more often seen in the mainland. Due to their ability to better blend in and relate to the Thedosians, they are the ones most often sent as emissaries, ambassadors, traders, scouts, and spies."