He does the things I want done. I am rating him on is his effectiveness at forwarding his agenda, and my own. You disagree with his agenda, so you rate him on what he does and how you disagree with it. We have different metrics of a sort.
As a counter example, Reagan to me was a pretty terrible President, although if I cared about a conservative agenda, I would probably rate him quite highly. That's not to say he wasn't a decent or inspirational figure who had some intangible qualities I like, but he did nothing beneficial to my vision of our country.