Much has been written on dietary simple sugar. It's controversial, so I can understand why the author may have skirted the topic. I thought the bit about tooth decay in chimps was a good hint that there are probably _some_ health effects.

I think what's interesting about this article is that one common bit of advice about limiting dietary sugar is that there's a big difference in the rate of absorption of simple sugar between fruit juice and raw fruit because the fiber content of raw fruit offers a natural means of limiting the rate of simple sugar absorption. But, if we are breeding extremely sweet fruit, it's a reasonable hypothesis that if such a "natural balance" of fiber and fructose exists, perhaps it has been undermined.