When we say that the data does not identify the designer that is a true statement when your focus is only on the science. DNA dose not bear a signature or copyright notice. Furthermore, because all scientific claims are tentative and because the singular events in question are remote unobserved and unobservable events that are not amenable to experimental testing one can not even be certain that the system is designed, from a scientific standpoint. To say that we know who the designer is, in my mind, a purely religious and not scientific claim. So, we should not be quarreling among ourselves about who the designer is when we are asking science to get rid of an irrefutable materialistic prejudice.First, we have the claim that the ID movement isn't trying to identify the designer. Dembski has maintained that the Designer could be aliens, though no one takes him seriously when he says it.
Now the claim that rejection of ID is based on "materialistic prejudice." If this were the case, scientists would have no problem with the alien hypothesis, since aliens are material entities. Since scientists have as little interest in saying "aliens did it" as saying "God did it," what's going on here?
The real reason, brought nicely into focus by the above paragraph, is that scientists have this nutty bias in favor of testable ideas. Until we meet some aliens, we have no idea whether they could have designed life on Earth or not. Until Michael Behe prays over a petri dish of bacteria and they miraculously sprout flagella, we have no idea whether God could be responsible for flagella on other bacteria. Attempts to set aside this "irrefutable prejudice" have had interesting results, but they are quite clearly in the realm of philosophy rather than science.