Actually quite a few Christians are very rational people. It is possible to use only some of the tools or rationality, to dig your own grave even deeper than you could if you knew nothing of it.

Becoming a more sophisticate debater for instance.

Those people don't consider "rationality" as something negative, far from it. They have their own idea of what rationality is, of course, but that idea overlaps ours enough that those two concepts can be considered to be similar.