I think it’s because people perceive a traditional or Victorian decor as being cozy and warm, and a contemporary decor as being cold and austere. In general, I think people expect cozy from a B&B, as opposed to cold and austere, so they decorate in the style that they think will appeal to the majority of guests. Also, B&B’s are usually in Victorian houses, so the decor has to match the architecture. It might be hard to incorporate contemporary decor into a house that has fireplaces, lots of wood trim, molding and wainscoting.