First, unless you supply a link to a claim made directly from a creationist stating that all mutational changes are maladaptive, this is a strawman. You state it is so, but I have not seen any such claim - and I periodically check in on these debates.
Second, what evidence can you proffer that micro changes have actually accummulated to the point of a chimp turning human, or a human chimp? Stating that it is theoretically possible is a far cry from stating it has occurred.
Here is a source a former FReeper “GodGunsGuts” used to post.
So you admit it is theoretically possible? What is going to stop mutational changes of some 2% genetic difference over some six to seven million years?
As far as evidence of the common ancestry of humans and chimps we have, not only the genetic similarity, but also the presence of ERV sequences that show common descent.
Do you need an explanation of what ERV sequences are and how they show common descent?
What follows is another Creationist disavowing that mutations can lead to advantageous adaptations.
It is not at all an uncommon belief among Creationists.
Please note how they link mutation to sin entering the world, thus all change from the “original Creation” that was “perfect” cannot be said to be adaptive; not if the original configuration was “perfect”.
http://www.angelfire.com/mi/dinosaurs/mutations.html
Mutations only corrupt the information already present. Leaving the organism with less genetic information, and a lower chance of survival.
This is in line with Biblical Creation, and the laws of Thermodynamics. The original Creation was perfect, and now because of sin it is starting to decay. The world and everything in it will continue to “unwind” and fall apart until the time when Christ comes.
The crazy thing is there are mouth breathing half wits who actually believe automobiles have "creators" or "designers." After all, you see more evidence of transitionary fossils at your local junk yard than in any rock sample!
What rubes!