It's easy for us to wrap our mind around physical rewards, since they can be quantified without much effort. Even Jesus spoke of dwellings being prepared in heaven and building up spiritual treasures for oneself. There wouldn't be money or houses in heaven (at least not in the traditional sense), but it was an effective frame of reference. So I'm not suprised that religious groups would use commonly-understood concepts to help believers idealize the spiritual.
The stuff about living in nice places left behind by the dead always struck me as quite gruesome. But we grew up in a poor and downtrodden area, and the homes weren't ostentatious or in good shape. The thought of it all being crushed and buried would have been more to our liking. I guess that's just about as creepy.