I think the point is that other games (Forza 5, Titanfall) are also unfinished but run significantly better.
That's because just chose a higher starting frame rate. That is, 60fps instead of 30fps. For obvious reasons of course, since both KZ and InFamous are going for a more open ended approach with a shit tonne more graphical quality and more going on in terms of visuals, graphical effects, assets, geometry, lighting etc.
TitanFall, like COD, goes the 60fps route and sacrifices graphical quality (Source engine is a pretty sub standard affair), and Forza, just like GT, naturally aims for 60fps. Most sim racers do. It's only arcade racers that tend to go for 30fps instead.