Not necessarily. The vast majority of propositions are false. Most of them are obviously false; we don't need to spend much mental energy to reject the hypothesis that "Barack Obama is a wooly mammoth," or "the moon is made of butternut squash." "Absurd" is a useful label for statements that we can reject with minimal mental effort. And it makes sense that we refuse to consider most such statements; our mental time and energy is very limited, and if we want to live productive lives, we have to focus on things that have some decent probability of being true.

The problem is not denominating certain things as absurd, it is rejecting claims that we have reason to take more seriously. Both evolution and Christianity are believed by large enough communities that we should not reject either claim as "absurd." Rather, when many people believe something, we should attend to the best arguments in favor of those beliefs before we decide whether we disagree.