You mentioned that eating all that fruit didn't raise your blood glucose, but from what I've read, that is not the true danger.
I'm certainly no expert, but apparently fructose is metabolized directly in the liver, and that too much fructose can screw things up. High fructose corn syrup (HFCS) is criticized for this reason, and I wonder if eating tons of fruit is harmful also.
Wikipedia says "Excess fructose consumption has been hypothesized to possibly cause insulin resistance, obesity, elevated LDL cholesterol and triglycerides, leading to metabolic syndrome." Fructose - Wikipedia, the free encyclopedia
Another source says this: "Because fructose does not produce a high GI, that masks the detrimental health impacts of it. What really matters to our health is not how fast the blood sugar rises but the impact on the liver..." Amazon.com: Customer Discussions: Does Taubes address the glycemic index?
And personally, my intuition says that we're simply not designed to eat that much fruit as a regular diet.