The pro-evolution community does have an anti-God bias, and admits it. Here are some quotes.

Creation Ministries International (previously with Answers in Genesis) has dug up a few interesting ones. Their book Refuting Evolution 2 discusses a Scientific American article, "15 Answers to Creationist Nonsense" by John Rennie (Scientific American, July 2002). They include this quote from the Scientific American article:

"Creation science" is a contradiction in terms. A central tenet of modern science is methodological naturalism — it seeks to explain the universe purely in terms of observed or testable natural mechanisms.

Unless one's mind is already utterly closed to the possibility of a divine creator, the flaw in this logic is readily apparent.

The book also quotes S.C. Todd, from correspondence to Nature 401(6752):423 (September 30, 1999):

Even if all the data point to an intelligent designer, such an hypothesis is excluded from science because it is not naturalistic.

The Rational Wiki, on the topic Methodological naturalism, says:

Methodological naturalists limit their scientific research to the study of natural causes, because any attempts to define causal relationships with the supernatural are never fruitful, and result in the creation of scientific "dead ends" and God of the gaps-type hypotheses. To avoid these traps scientists assume that all causes are empirical and naturalistic — which means they can be measured, quantified and studied methodically.

If there is a God, then this "naturalistic" line of reasoning will reach a wrong conclusion when it comes to the question of origins. Isn't the scientific method supposed to be a good means of finding truth? But if it turns out that the truth does involve an intelligent designer, then the naturalistic approach is destined to fail to find the truth.

The argument is that invoking "God" adds nothing to scientific knowledge. I would argue instead that excluding God adds nothing to scientific pursuit, and in fact diminishes from the pursuit of truth.

Many fields of science don't directly address the question of origins. A Christian can sensibly believe that God created an ordered universe that behaves according to pre-defined laws, and therefore engage in scientific research of the world according to the scientific method. The assumption is that God doesn't maliciously or on a whim override these laws, but may choose to do so on occasion to accomplish His purpose. Thus many Christian scientists have made useful contributions to the body of scientific knowledge.

Making a wrong initial assumption (either for intelligent design or for naturalism) may not be a catastrophic disruption to scientific discovery in some fields, but it may slow the progress of scientific discovery. But when facing the question of origins, it is even more essential to strive to avoid bias, and not exclude any possible options from the outset.