There are a number of reasons:
According to some Facebook articles, Wisdom teeth are key to the health of your liver because the nerves in your teeth are linked to other areas of your body. Clearly all your nerves are connected through your brain, but removing this tooth will not damage your liver. The article is right that there are risks of Paresthesia (temporary or permanent feeling loss) after the extraction, however this is a risk, albeit less of one, in all extractions and oral injections. This usually only lasts for a couple of weeks to a couple of months. This article would also have you believe that wisdom teeth are removed because our hygienists are lazy, and don’t want to clean them. We always want you to keep all your teeth if this is a possibility, and if we all had the room for our wisdom teeth to come in and not cause issues we would see a lot less of them extracted.
There are treatments available that can reduce the risks of these extractions by uprighting and allowing the wisdom teeth to erupt fully into the oral cavity. By erupting the wisdom teeth we may allow them to either be kept or be removed by less invasive methods. Talk to your dentist to find out if the option of uprighting your wisdom teeth is for you. What do you have to loose, besides the teeth that you were going to loose anyways.