Earlier quoted context omitted.
Well, one can damage a hardcover by not opening it properly the first time: https://www.reddit.com/r/lifehacks/comments/7sry7v/open_a_ha... (which was a lesson in 2nd grade, when we got our first-ever hardcover textbooks)
That's sure can't be true for "modern" (as in 1960s+) books? Bookstores normally allow to look inside hardcovers without being instructed on proper handling first
Typical glued texts are more prone to this, but depending on the state of the glue, may go back so square if pressed when square to correct.