If you're driving around with a big hole in your car's plastic bumper, you need to stop. There's no reason to disgrace your beloved car or truck by subjecting it to ridicule due to the gaping tear in its otherwise beautifully painted plastic bumper cover. Seriously though, even a minor accident can result in a damaged bumper. Sometimes you're lucky and you can get away with simply sanding and painting the damaged area.
I took a walk today to get some pictures of bumpers, and common bumper damage, and what I saw confirmed my thinking. A huge number of late-model cars with painted bumper covers had all sorts of damage from apparently small incidents including paint scratches, scuffs, punctures, cracks, and big caved-in areas. Even bumpers on more rugged-look cars, like Jeeps or FJs that aren't painted are still brittle plastic caps over mostly empty interiors, so they tend to crack and cave in like any of them.