Why, in the face of so much convincing evidence, do people still not accept evolution as a process that occurs to shape the existence of life on this planet?
Because if you get in the habit of ignoring evidence, then you can believe anything you want. And the more practice you get at ignoring evidence the better you get at it.
It is not just the evidence for evolution, but the very idea of evidence itself which is being rejected, so that it becomes possible to live in a world, where the truth is anything which tells me what I want to hear, and my truth never tells me anything that makes any demands on me.
Because accepting it can bring all of their beliefs about special creation, original sin, etc into question.
Those who do accept evolution, think it was with the guiding hand of their god; but those who deny it cannot allow even that possibility. If one questions the literal truth of any aspect of the Bible, one has to question all of it; and they simply cannot allow that to happen.
People are guillable, scared, herd mentality primates that can conceive of thier own death and fear said death. Of course some assholes have figured out ways to milk that for all its worth with some fantastical, pretty freaking appealing fairytales that are extremely easy to believe. Evolution directly contradicts certain portions of some fairytales so it can't be true.