50 percent of the population are below average IQ.
So even 20% of those people who are dumber than a box of rocks know that creationism is a joke.
The problem: No version of creationism requires belief in infinite sequences of probabilistic miracles and outright zero-probability events as does evolution. In other words, a reasonable person could at least listen to a theory which demanded one or two probabilistic miracles but evolution stands everything we know about modern mathematics and probability theory on their heads. In other words, ANY religion is better than evolution, including Voodoo and Rastafari.