Hmm... well, my 2 cents (not worth anything but throwing my hat into the ring regardless): I've re-read many books (both fiction and non-fiction) that I've personally truly enjoyed more than a handful of times. Do the same for movies and music obviously. A visual novel is no different. So replays, that's only natural if you enjoy the product and one reason why I mod to "pay it forward" and help bring new eyeballs to a product I personally enjoy that might have otherwise never known the product existed.
Bottom line, ain't nothing wrong or odd with studying and re-consuming media you enjoy, you've done it since birth, it's in our DNA as conscious beings. Please enjoy art, be well, and kind to each other. Kindest regards.