SCOTUS is not apolitical. (No human institution is.) That doesn't make it a political body.
I've found helpful to read the official opinion of decisions I disagree with. Start to finish, including the dissent. With respect to modern rulings, I have yet to walk away finding the arguments abysmal. In almost every case, I disagree with the law, not the court.
When I disagree, it's because the law--as you say--had holes. The court fills these in, by necessity. On this, it's fair to find disagreement. But the degree to which these holes are filled is usually impressively restrained. There are very few modern case where, given the facts and circumstances of the case or controversy, and within the context of the surrounding law, I found the interpolation obscene.
> not on the level that you find in actual logic, math, or computational science
Courts aren't deterministic. That doesn't make them a political body.
It's an open debate as to whether we want the law to parse like code. I don't. As long as lawmaking is under human control, the law is comprehensible to humans and humans remain free agents, the law--and thus courts--will have a degree of unpredictability to them.