Is it bad to eat too much fruit?

You can eat too much of anything... but generally speaking, it's easier for your body to process "too much" fruit. If you think about ancestral hominids 200,000 years ago or so, they'd of come upon some fruit trees, or berries, and eat as many as they could. Maybe they went a few days without food, and came upon these berries, so they pig out. It's far more painful to overeat bready foods.