Hmm... background textures motivating someone to read is one of the weirdest things I've heard.
I understand their visual attraction, although I don't use them myself. But what motivates me to read is the book itself. If I feel bored or unmotivated, I'll ditch the book and start another.
Of course it's no skin off my nose whether BookFusion and other apps support background textures or not, as I read 99% of the time on my eink readers anyway. If they're important to other users, fine. More features is always better than fewer.