It's more logical that the low ISO performance is great than that the high ISO performance is great.
...makes the assumption we can all shoot at low ISO most of the time, as you apparently can (and here I'm assuming that with current FF sensors, ISO 1600 isn't 'high'). For those of us that routinely need to shoot at greater than ISO 3200, your logic doesn't apply. That's the bias to which I was referring.
Ideally, we'd have great performance at low and high ISO, and everyone would be happy. That's solidly in the fanciful land of 'IF' for now.
What I meant with that is that it's more logical from a technical point of view. Not that I or any other person prefers very good performance at low ISO. Everybody knows that raising ISO means more noise and less DR.
Take a look at these 2 examples:
1) a runner with a heartbeat of 70 bpm (low ISO)
2) a runner with a heartbeat of 180 bpm (high ISO)
Which one most likely has to stop to catch his breath?