I, like the others so far, prefer A to B. It feels richer and stirs my emotions more. But it's a pretty close call. I think A is human and B is AI, for the same reasons. In addition, for some reason, I think and AI would write the shorter paragraphs of B, though I don't know why I feel that way.

It would not surprise me at all if both were AI written. I doubt they were both human written, not because of the writing, but because it would make the point of the column weaker.

I am curious that the construction of the two articles is so close; it is hard to believe they were written completely independently, from the same prompt.

I also wonder if the results of your experiment would be different if the position of the two articles was swapped. I suspect most of us took a side as soon as we read the first paragraph of the first article.