Another reason is people other than the writer want to make their mark on the project and the title is the single most prized sentence in the entire book writing enterprise, and it’s easy to express opinions about it (whereas opinions on the text of the book itself requires hours of investment).Many books are chosen by editorial committee and you can guess which ones they are.
And most of them would be wrong about the results (See #4). We assume our instincts and likes are matched by everyone.
Depending on how many book titles you look at a day, your place, and your reader’s place in that timeline is different.
What seems played out to you might be on the rise for your audience.
Everyone is very happy to tell you how to pick a title, and in particular, that you are doing it wrong.
A special joy comes from people telling you that your title ideas stink, yet who can’t offer a single better alternative.