Unless one wishes to invoke the omnipotent intervention of the supernatural, then all reasonable people would agree that methodological uniformitarianism provides a basis for rational scientific discussion.
I know that in my profession of geology, the science has grown exponentially in the past 50 years. To think that reasonable scientists would not modify or re-think their ideas in light of new evidence is laughable. I was lucky enough to work on projects, such as the Deep Sea Drilling Project, that provided powerful evidence for the hypothesis of sea floor spreading (plate tectonics). I was also fortunate to work closely with some of the top micropaleontologists in the world. Micropaleontologists work with the smallest of "God's creations." These tiny, yet amazingly complex foraminifera, diatoms, etc. tell a story of morphological evolution unlike any in the macroscopic world. By comparing the forms observed with the depositional environment recorded in the rocks, one can observe slow, steady evolution during environmentally steady periods of time, and rapid morphological change, extinction, relocation, replacement, and re-population during periods of climatological and/or geological upheaval. The evidence is all there, preserved in all of its microscopic detail.
Which gets me back to my point. You set up a generalist strawman comparing catastrophism and uniformitarianism and drew conclusions from it. Your implicit point was that creationist world view was unchanging. (That world view is not surprising, given that it is more-or-less based on a literalist interpretaion of the Bible.)
You asked the question, "Which group had to change?" Let me restate the question as, "Which group is willing to learn and grow?"