I agree with Jonno here. I have met many people that have grown up in countries without snakes and they don't have the same pathological fear of reptiles as those that grow up in countries with them.
I think the blame can be placed, in part, on parents and caregivers. So often around children you hear the cry "don't go down in the long grass <insert appropriate area here> there could be snakes!!" delivered in a panicky voice.
"Watch out for snakes"
"The only good snake is a dead snake"
etc
It is growing up with this mentality around us that creates the fear. Mother, Father, Grandparents all tell the children to be careful of snakes, therefore snakes must be something to be greatly feared indeed.
Spiders also generate this type of fear and again, as children, we were told to keep away from them. A little example here...
I didn't want my daughter growing up with pathological fear towards spiders, snakes, anything really. So I never used those panicky warnings and instead, encouraged her to keep her eyes open, and if she saw something, not to touch, but to come and get me, so I could see it too.
She was very good at doing this, would happily watch spiders from the other side of a window and showed no fear. Then one day, she started freaking out at them and I wondered what had happened. I soon discovered her Grandmother was at fault. Her Grandmother had seen her watching spiders through a window and had freaked out, given her a big scare talk and my little 3 year old had developed a fear due to that. It took me a little bit of work to get her over this fear and a stern talking to Grandma not to repeat the behaviour, but it worked, and again, she is not scared of spiders, but has a healthy respect for them.
OK, that went on a long time. Fear of snakes is not instinctive, it is learned.
