Every professor has their own style, most of the ones I had were very open that office hours were a pretty great way to get help/more targeted hints on what to study. This isn’t in my opinion, a problem. Their goal is to educate you as best as possible in theory, via classes, homework, and office hours. Students who take the time and effort to attend office hours clearly want to at least pretend to be putting in extra effort, so why wouldn’t they out more effort into helping them learn? I doubt that they are directly giving away test answers.

For many profs the goal is to spend as little as possible time with students, so that they can spend more time with their research career, than lectures for students or hours after the lectures. For that they employ students, who have passed the exams. Teaching is merely a necessary annoyance to them.

The problem with targeted exam hints on what to study is that it can create situations where a student who understood the material better overall and put in more effort studying all the material equally, scores lower than someone who simply happened to get hints from the professor. If your actual goal is to educate, you shouldn't give exam hints, and especially not one-on-one.

In an astrophysics class I had in college , the professor called on a student to solve a problem, he got it wrong, and the professor said "if you would come to my office hours you would know how to solve this" - the students response was something along the lines of "sorry, my parents are crackheads so I need to work two jobs to pay for school"