Sure, but I don't think the debate is over whether creationists derive a sense of purpose from their beliefs. I have no doubt that they do. You'd never need to discuss things like fossils or evolution or cosmology to determine whether one derives a sense of purpose from one's beliefs.
My assumption was that these debates are about the epistemological status of these claims, which is largely independent of whether one derives a sense of purpose.
If you're spending lots of effort making what appear to be good-faith arguments toward some conclusion, but that conclusion is in fact an axiom that you hold, then that's intellectually dishonest. If "Bible is true and scientifically accurate" is one of your axioms, then it's intellectually dishonest to provide some supposed piece of evidence that supports this claim (e.g. supposed missing links in the fossil record), because by definition 1) no evidence is necessary to support an axiomatic claim and 2) no evidence or explanation can possibly change your mind.
Now, I am not going to defend Kent Hovind's intellectual honesty. I think he does have a not-so-hidden ulterior motive (tax evasion). But you cannot legitimately accuse him -- or any YEC that I've encountered -- of trying to paper over the fact that he assumes the truth of the Bible.
But there is no intellectually honest way to reconcile that factual claim except to reiterate that it is an axiom (or, if you like, a trivial corollary from the axiom that the Bible is true). The supposed existence of missing links is completely irrelevant, because even if those links weren't missing, his conclusion would be that evolution is false. Ancient flood myths are completely irrelevant, because even if such myths weren't widespread, his conclusion would be that evolution is false.
To clarify, I'm not claiming that creationists conceal their beliefs about the Bible. I'm referring to intellectual dishonesty.
Explanations of this form are extremely easy to vary, which is why they are not good explanations.