For the most part, wheel graphics are cheesy. I've had some so obnoxious that I scraped them off but I start with them in for the same reason I have solid black grip and prefer simple graphics (or plain shirts and subtle shoe styles for that matter), to reduce the busyness. I just don't like a lot of flair. On the other hand I've heard people say they wanted to preserve their wheel graphics so they put them in to reduce scraping on the ground.
It's not a new thing, most people I know have been doing it ever since symmetrical wheel shapes came out. They end up getting rotated out before long anyway to prevent coning as they wear, but by that time rubbing on coping/ledges has taken most of the paint off. In the end it doesn't matter. It sounds cliche but put them whatever way you want and don't worry about why other people do what they do.