John Cena is renowned as 'The Face' of WWE. 

For almost his entire professional wrestling career, the 16-time world champion played the role of a 'good guy' and after establishing himself as a top star, never turned 'heel'.

That was a move that always frustrated fans, who would boo Cena regardless of the fact he was always positioned as the 'face' character in storylines.

It's incredibly rare for a WWE Superstar to stay as either a 'face' or 'heel' for their entire run, but 'The Leader of the Cenation' was never turned. 

So why, exactly, did Vince McMahon refuse to do it? We may never know for sure, but speaking on the Grilling JR Podcast, Jim Ross speculated as to why.  

"The thing that’s always been funny to me is that Cena never turned heel. There’s where my brain fart starts. Why didn’t we do that? Why was that not done?" he questioned. 

"I’ve heard John didn’t want to be a heel, I don’t really believe that one.

"I just think that Vince felt like he was such a pristine baby face but if you listen to the audience, there was a long time there where he wasn’t a pristine baby face."

JR then went on to question why Cena was booed so much by WWE fans and eventually compared him to today's top heel, Roman Reigns. 

"The audience more often than not will tell you what they want to buy, they will tell you what aisle to go down with your shopping cart and tell you what is in your cart to take home. 

"You just listen, listen to their reactions. I was always amazed that Cena got booed so much.

"Cena getting booed was a lot like Roman Reigns getting booed whenever he was just getting rolling, and now there’s a reason to boo Roman Reigns because thanks to Paul Heyman, he’s become a significant antihero.

"He’s a heel, and he’s a damn good one. The Cena thing, I never quite understood why we didn’t pull the trigger on that deal."

Many fans can't understand why Cena was never turned heel either, but Ross' suggestion does certainly help explain the situation.