I guess it’s just the difference between having the desire to display them and not caring about that. I am also a person who likes worn books - I believe rehoming used books is a more environmentally friendly choice and I also don’t care if they’re pretty and perfect when I put them on the shelf. I don’t mind if they look like I’ve actually spent some time with them - I feel that is the point. I respect that some people want them to look pretty but I think that’s kind of silly personally. I do understand wanting the experience of the book looking new if you are buying it new because you like it that way. There is something pleasing about a brand new book. I just personally wouldn’t bother much about keeping it that way. But no disrespect to you and your personal preferences.

Edit - ALSO when I get a secondhand worn book it is cool to imagine the people who have spent time with the book. For that reason I also enjoy other people’s marginal notes and various markings as long as it isn’t overboard.