I don't think I am saying that. I am saying that the radius of curvature of a peak is potentially greater than the typical step size used in A/B testing. No discontinuity is needed, the landscape could be completely smooth.

I'm not suggesting that the extreme of text + css only is what epitomizes a good minimalist page either. I'm just pointing out that it is absolutely not a given that A/B testing has shown that the global maxima is not near it.