More that ideology trumps rationality. People are not rational most of the time, and really wanting to win blinds people’s judgment even more. (Witness the recent current events…) I bet it all makes sense in their own minds in some convoluted way because they have decided “science” can’t be trusted and is in league with the devil.
Dishonesty implies intent to deceive. I don’t think they intend to deceive because I think they see everything as defending undeniable truth. You could argue that there is definitely intent to prevent people from ever coming into contact with threatening ideas, even if it means grossly misrepresenting the opposition. Is that dishonest? Or is it a symptom of the twisted kind of paternalism that runs rampant in Fundamentalist leadership? I am suspicious of groups that are making a lot of money off of creationist propaganda and I do question their motives and honesty. But I think the rank and file are just trying to be faithful to the faith as it was taught them and don’t feel they have a choice. I talk a lot to people who have “escaped” Fundamentalist churches. Depending on how dysfunctional their family/faith community was, it can really do a number on a person’s mind that takes years of counseling and healthy relationships to work through.
Again, I think this makes sense to them. They preemptively reject the idea that any rocks are more than 6,000 years old and think all scientists who claim otherwise are playing a big fraudulent game. In their minds, all scientists who send rocks to that lab are sending rocks less than 2 million years old, so how is it dishonest for them to do so? It just shows that when you categorically reject basic premises of a discipline (i.e. rock strata dates can be estimated based on observable features) you can’t really understand the discipline.