Sugar. You like it because it's loaded with sugar. I don't like tomatoes, fine with ketchup and salsa. But not pico, because the tomatoes in pico are still too tomato.

I was the same as you until I had some really flavorful, not gooey or watery at all tomato sliced. If you can get heirloom tomatoes near you I recommend them fully. They're more expensive, but you need fewer of them