Meh, you have three choices…
Play the game and avoid the locations the spiders are in. Spider spawn locations were posted in this thread. Trade for silk if you really need it with someone on your server.
Face your fears and slaughter the computer animated spiders since they don’t exist and can’t hurt you.
Maybe this just ain’t the game for you. If survival crafting is your style there are plenty of other games in the genre that don’t have spiders in them. In short, play something else.
Those are your options, you do whatever you want out of them.
Because let’s be honest here, they aren’t going to take development time and money to take them out for a few people. And then where does it stop? Plenty of people have the same fear of snakes as you do of spiders, should they be taken out too? Plenty of people are afraid of dogs, should wolves and hyenas be removed? Plenty of people are afraid of lightning and thunder, should that be removed from the Highlands? etc etc etc…