It's hard to bring something to a BBQ that people will like that's still simple and quick to throw together. Throwing a few bits to fruit onto a stick is pretty much as simple as it can get. And who doesn't like a rainbow! You can dress up that boring buffet table covered in potato salad and baked beans!
Finger jello is super fun even when it's only one color and just hanging out by itself. Taking the extra time to layer a whole bunch of colors in there takes it to a whole new level of snack innovation. I wonder how it tastes with all those flavors in one mouthful? Like a rainbow of fruit?