Just because it's common that does not make it rational.Jerome9157 said:Wikipedia: A phobia (from the Greek: φόβος,phóbos, meaning "fear" or "morbid fear") is an irrational, intense and persistent fear of certain situations, activities, things, animals, or people.
Being "irrational", it is expected that relatively few people suffer from the affliction, however, fear of spiders is very common.
This technically means its the "Norm", and not so irrational.
If this is the case, Arachnophobia itself is an oxymoron, and Arachnophillia is the obviously irrational form.
To test this theory, I ask you, Are you Arachnophobic?
Most spiders can't actually hurt you in any way, it is therefore irrational.
Speaking as an arachnaphobe being so scared of something that you can't work up the courage to drop a heay book on it is likewise in no way rational.
EDIT: Also you obviously have no idea what an oxymoron is, that isn't even close.
An oxymoron is a combination of words that contridict themselves, eg "A deafening silence", "A full half" or "a sober brit".