Roman Reigns analytics (Google trends, YouTube views, minute by minute TV ratings, merchandise sales etc.) are superior to his peers who are not legends hence his continued push.

"WWE is coming off a period where the prior top face, John Cena, was routinely booed most weeks on television, heavily in the larger markets, and even more on the big PPV shows. At the same time, nobody in the company moved merchandise, sold tickets, & for much of that period, garnered response, both positive & negative like Cena. With Reigns, in many ways you have a lesser Cena. His personality isn’t strong. Like with Cena, he’s far from the best or most versatile in-ring performer, but he works hard every night. Like Cena, he can have tremendous matches in main events and then people criticize him as a bad wrestler. The audience at Fast Lane and at Raw booed him heavily when he’s supposed to have his most momentum building to his big win. At the same time, he does well in main events at house shows. His merchandise numbers are good, although nowhere near Cena level. He has the look to be a star and he’s a great athlete who works hard. Perhaps in another era, based on the standards of that era, Reigns would be the guy to lead the company for the next five years. But no amount of knowing what used to work or thinking what should work can cover up, that today, this didn’t work. You can analyze why, and I’ve heard it from the smartest guys in the business, and some who may not be so smart. But none of those reasons, whether they are right or wrong, changes that no matter how things should have gone, and how crowds should have reacted, they didn’t. Business is what business is. There are no major difference makers, except maybe for a unique match here and there. Whether Roman Reigns or Sami Zayn or Dean Ambrose is the face of the company, it’s not 1987 when you change the world champion and put the wrong guy with the belt and business goes to hell. The story of the last several years has been the struggle between the hardcore fans and the decision makers. And in the end, none of this seems to have any bearing on the bottom line." - Dave Meltzer