Disease. Cockroaches do spread disease.

Studies show that cockroaches are responsible for the spread of 33 types of bacteria, six varieties of parasitic worms, and seven types of pathogens. Cockroaches can spread germs and diseases including:

• Diarrhea
• Cholera
• Typhoid fever
• Leprosy
• Dysentery
• Plague
• Poliomyelitis
• Salmonella
• E. coli

I grew up in poverty. When I was about nine years old a cockroach crawled in to my ear as I slept on the couch. The sound of that thing stuck in my ear still haunts me. Cockroaches need to die.

You seem to be mixing the concept of being startled and being afraid. Most people can be startled if something moves unexpected across the floor but that is not fear.

Would you refuse to go in the kitchen if a cockroach has been spotted in there? That is fear.

I would not go (or would definitely hesitate to go) into a room where any of wild dogs, snakes, wolves, hyenas, wild hogs, or bears were loose but a few cockroaches wouldn't stop me.

As others have said: they're nasty. There are a myriad of health risks associated with roaches in your home. They definitely do us harm, albeit not as directly or obviously as, say, ticks or mosquitoes.

I consider my fear of roaches to be entirely rational. They directly carry diseases, and they produce allergens. They exacerbate or even cause Asthma. Also, it's never good to have decaying corpses of any type inside your walls, which is where they will end up if you have an infestation.

They will eat anything. They will go anywhere. They will thrive anywhere. I've seen wallpaper come right off the wall because roaches ate all the goddamn glue. You cannot get rid of them without a whole lot of poison (if even), which is itself a health risk. If I see a roach, I go to DEFCON 2. (DEFCON 1 is reserved for bedbugs.)

Where I live, we have a problem with American cockroaches. American cockroaches are a good news/ bad news kinda deal. The good news is that they nest out of doors so they don't live in your house, and their presence is not necessarily a commentary on your housekeeping.

The bad news is that they will get into your house and they're about 4 times bigger than the German cockroaches that everyone is familiar with. You can hear them crawling, and they can fly.

I asked the exterminator how to get rid of them for good, and his advice was to move.

Some excellent answers here.

I would add that it's not always fear necessarily but also disgust. Cockroaches are associated with filth, so the presence of a cockroach makes people feel disgusted and uncomfortable. For me, if I see a cockroach it means the place I am in is dirty and unhygienic, and that is enough to cause revulsion.

A lot of the examples you give bar spiders are not things you'd find in your own home. Cockroaches are usually something you'd find in a dwelling where you'd naturally feel safe and separated from nature. Seeing a cockroach in your home or a place you're staying / eating is different because it's an invasion of your space, and by a creature we associate with filth.

I think there's a misunderstanding here. I'm roachphobic - this doesn't mean I'm afraid of roaches, it means I hate them and want to murder them all.

Apparently the feeling is mutual. Studies have shown that if you touch a roach, it will find a safe place and then clean itself.

Cause that's how we got taught, there's a video where they put a snake in a baby playground and they barely reacted, some even touched it. That to say that some fears are taught.

~~They come up a sewer pipe and then walk around looking for food in the kitchen. Bad combo.~~

EDIT: I got caught up responding to what I considered misinformation while not addressing the question that was asked.

Sounds like you've never had to deal with a roach infestation. The worst I ever encountered, in the basement of a slumlord shed following a big flood, looked like the subway scene from Cloverfield

Cockroaches, blattodea, are hated because they're resilient and some thrive in residential settings. If they were easy to get rid of, or lived outside (most actually do), they wouldn't be so vilified.

Another example of insects hated for their resiliency are bed bugs. But those have even more impact on your life if they infest your house. Eusocial animals like termites and ants are more susceptible to pest control so we don't care as much.

The truth is that many types of arthropods have extreme resiliency, but they don't like to infest buildings, so we don't really care.

Source: studied entomology

Because they're basically land shrimp that can survive nuclear fallout.

You should be afraid.

im afraid of a whole bunch of the things on your list when they are actually in my vicinity.

The fast movement and lack of sight is what's scary about them, snakes tarantulas will move away from you and do it slowly, cockroach will run in any direction at full speed when startled unless you explicitly startle them with large thud near them, otherwise they might dash full speed towards you

Also social upbringing making them out to be some great threat and fact we're way more common to see them than the other actually dangerous creatures

I don't know but the palmetto bugs here, I have an irrational level of fear of those. They will fly AT you. Just writing about them freaks me out.

I am sure they have a place in the world, and a function. But if I never again see a flying mating swarm of them it will still be one too many times.

I love spiders, love snakes. Rats are so interesting and clever. Love vultures and crows. Bugs in general I don't like except ladybugs, dragonflies, bees, and butterflies but only the overgrown roaches really terrify me.