I don't think that is what GP is commenting about. He is stating that previously one of the arguments for iPhone was that the weight was just right. Any less or any more would have destroyed the form factor.
While I had not seen this argument with weight, I have seen it multiple times with Screen Size. And now that it has changed I am pretty damn sure that 4inch screen will not be the only form factor that is perfect and everything else will be 'not-for-the-masses'.
Why is it a bad thing that they've innovated to the point where they can get the level of quality they're happy with and lowering the weight?