I think the problem most people have with determinism is the fear that their life is predetermined or predictable.
Predetermination implies a predeterminer, frequently referred to as GOD, but even the people who believe in GOD, think they have free will. If there is no predeterminer, then there is no predetermination OR predestination.
Predicting which way a particular human being will develop is, pragmatically, impossible. The number of variables which come in to play are literally astronomical. Personally, I'm intensely interested in astronomy, so to predict my future behavior, you would need to know the current condition of ALL astronomical phenomenon and how they will develop over the course of my life. Good luck with that.
You may believe in free will but, given everything you've experienced, what choice do you have?