4. John Cena
John Cena originally arrived on the scene as the Doctor of Thuganomics and stole the spotlight as one of SmackDown's most charismatic heels. However, he soon became a fan-favorite, winning the US Championship at WrestleMania XX in 2004, becoming an incredibly popular superstar. That eventually led to him rising up the ranks of the blue brand before he won the WWE Championship at WrestleMania 21 the very next year.
After he moved to Raw, everything changed and fans began to grow weary of the company's blatant attempt to force him down their throats as the next face of WWE. He did become the face of the product, mainly because of his popularity with younger fans, and that led to the product becoming more kid-friendly in the process. The real thing that turned fans against Cena, however, was how he constantly came out of every feud and match looking stronger, essentially burying his opponents along the way.
This went on for years, with the careers of the likes of Bray Wyatt, Umaga, Wade Barrett, and Damien Sandow either significantly stalling or never recovering from ending up on the losing end of feuds with Cena. "SuperCena", as fans so aptly called him, couldn't be beaten and once that golden shovel came out, good luck carrying on with your career.
Cena's good guy character was bland and uninteresting, and it wasn't until much later in his career that he actually started wrestling decent matches, and yet the company continued to push him to the forefront of the product, have the commentators try to manipulate viewers into believing that he's "the greatest of all time" (when he clearly isn't), and defeat far more gifted opponents week in and week out. And no amount of "Cena sucks" chants, or loud, vocal boos from the audience would change that.
Now only returning to the ring occasionally, Cena is rightfully respected for all that he has accomplished, but wow did he find himself on the wrong end of fans' ire throughout the majority of his career. There may never have been a more divisive superstar.