Atheists claim Creation Science isn't really science while creationists claim it is. Historically, which is correct according to the scientific community and why do they say this? I hope this is not off-topic, but I don't know where else to ask this.
The "Scientific Community" is an abstraction, rather than an organized group with stated positions on things, so a strictly factual response on what they believe is probably impossible. No doubt there are scientists who believe Creation Science is valid science.
But several groups and organizations have addressed the question and found the negative. In the Court case Kitsmiller v. Dover Area school district, the court found ID wasn't a science, based in part on measures of the scientific community as a whole. And most of the relevant professional organizations for biologists have released statements against the idea that ID and Creation Science are sciences.
Just as an example, heres part of the American Institute of Biological Sciences statement on a Bush-era attempt to encourage ID in the classroom:
Intelligent design is not a scientific theory and must not be taught in science classes," said AIBS president Dr. Marvalee Wake, a perspective shared by President Bush's science advisor, Dr. John Marburger III. On Tuesday, August 2, Marburger stated in an interview that "evolution is the cornerstone of modern biology" and "intelligent design is not a scientific concept.
Googling, you can find many other similar statements from both the AIBS and basically every other similar organization in the US.
So to the extent that the "Scientific Community" has a position on the subject, I think its pretty clearly that Creation Science is not a science.