Consider this.
Cockroach wings are exactly the same shape as grasshopper wings, and grasshoppers cannot fly. They can only glide along. Cockroaches are essentially the same except their body shape is in much worse condition than a grasshopper’s, so they can’t even glide as well as them.
So when a cockroach flies, it has no idea where it’s going, and it can’t control itself very well. It could even bump into you.
On the opposite side, consider a horsefly. When it flies away, it’s really fast and very well coordinated. It can control its flight very well, so it will do everything it can to avoid you while it’s flying away.
Cockroaches are slow, chaotic, and uncoordinated.