Hardbacks have two great joys: their hard cases and the fact that they will open flat and stay open at any page. This they can do because the book is made up of folded sheets assembled into sections and sewn. Perfect bound books consist of sets of single sheets glued along the back. Paperback covers are light and so the book can be tortured into staying open, whereas perfect bound hardbacks need to be held by at least one hand and probably two if they are to be read at all.
Of course, it is obvious why publishers are doing this. It is cheaper and they can still charge the same as before for the book and pocket the difference. I never buy perfect bound hardbacks. I either wait for the paperback to appear, or borrow the book from the library.
J G CUNINGHAME