The real reason he, and others, expend such time and energy convincing themselves is rooted in the dire implications for them of the truth of the contrary. It's not what is true. It's what do I wish to be true. The fact such a large body of respected men, driven by this desire (read summaries of their biographies), makes it that much easier.
There's no reason I can't take the most absurd theory - that the earth is made of cheese - and interpret all incoming evidence to support that postulate. This one - biological macroevolution - just happens to fill, if true, a common desire among many: to obviate final accountability to a supreme and righteous Diety. That is the real reason for its popularity, and why it has become the dominant hermeneutic for interpretation of natural evidence.