Why aren't Rush Limbaugh's comments on the oil spill getting more attention?

Recently Mr. Limbaugh explained his belief that rather than being BP’s fault, the recent oil spill was actually caused by The Sierra Club. He has also said that the money being spent to clean the spill is wasted because these massive amounts of oil are natural and if left alone it will fix the problem. Why is he able to spout this stuff without being called out loudly?