Why do we kill spiders and scorpions but eat lobsters and ?

The best way I can explain it is how we encounter the creatures. Lobsters and are served on a plate, red in color (by the time I see them), and are accompanied by er to dip them in. Spiders sneak into my house and scare me half to death with their quick little movements and creepy ways. If they were dead and I was used to seeing them on a plate for me to enjoy as a snack, I might feel differently toward them. Now if a live lobster or crab was in my house, I'd freak out too! That would be more terrifying than a spider for sure.