I actually know someone who used that little decorating trick.  Well, she wasn't/isn't a reader of any sort and she felt old books gave her room the look she wanted, and I suppose there is a kind of sincerity in that.  I had to bite my tongue--hard--when she told me straight out what she was doing.  Interestingly, one of the books she parked on the shelf actually had meaning to her because it had belonged to her grandmother, a charming tome on true womanhood.