One of the reason's people hate to accept Cena is not because of his moveset, but because he just isn't convincing enough and hasn't grown onto them.
Most people have said that Cena isn't championship material or shouldn't have his first title in 2005 because he wasn't ready for it and didn't have the proper push for it.
Cena's mid card push 2003-2005:
Sure Cena has had feuds with some big names during his early years. He faced off against Jericho (2002), Kurt Angle, Brock Lesnar, Eddie Guerrero, Chris Benoit, Big Show and Undertaker. However he lost against all those big names, expect that one time against big show at WM20. He just didn't feel strong, he faced all those big names but couldn't be taken seriously due to the fact he was unable to defeat them.
Let us not forget, 2003 was probably cena's best year in many fan's opinions, he was a great heel, great mic skills and very entertaining. His face turn in 2004 wasn't as great as his heel performance in 2003. However, when Cena did get over and win matches, it was mainly against other midcarders like Rob Van Dam, Orlando Jordan, Rene Dupree, Booker T, Carlito and Kenzo Suzuki.
When he finally defeated JBL at WM21, that was his first and perhaps only big name he ever beat during that time. This is why he felt so weak as a champion, he couldn't beat those high carders mentioned above during his mid card push, some people just didn't buy it. Sure JBL had a lengthy reign but he cheated almost every time to keep it, hardly won a clean match and therefore seemed weak when Cena beat him.
What is more ironic is that AFTER cena won his first title, he went on this streak and defeated guys like Kurt Angle, Chris Jericho, Triple H, HBK, Kane, Chris Benoit. Why couldn't they have cena defeat some of this big names during his mid card push? It could have made him look much stronger - sure he didn't have to win all the time but maybe one or two big victories against Brock, Angle and Taker would have helped a lot.
Cena's push was really reversed, he first was put to feud with huge names in 2003 to which he lost to almost all of them, then in 2004 he feuded with mid carders and won against all of them, and in 2005-2007 he feuded with high carders and won.
What should have happened was Cena should have feuded with more mid card guys in 2003 and lesser high card guys. Such as perhaps Rikishi, Matt Hardy, Rey Mysterio, Edge, Benoit and Eddie... beat them all, but even loose a few matches against Edge/Eddie/Benoit. Then in 2004-2005 have him feud with Big Show, Taker, Lesnar, RVD, Booker and defeat most of them cleanly. And then around late 2005 he would have been ready and established as a legit high carder instead of completely destroying the roster from 04-07.
Can't blame Cena, WWE was in a rush trying to push a younger talent in 2004 since Brock, Rock, Austin, Foley, Goldberg and many big names were leaving. They rushed his push, ruined his character and kept him face too long, his thug gimmick as face just wasn't as fun as it was as heel. The John Cena of 2003 that all the fans knew and loved was gone, he was a shell of his former self, no longer rapping and was completely different and bland - the fans back lashed, they didn't like the Cena of 2006.
2005 he was still rapping but it was more watered down, the fans still supported him but 2006 they got very frustrated with all the changes in his gimmick.
If Cena was pushed right, slowly and properly, he would have been the Stone Cold/Rock of this generation. He ISNT the Rock/Austin of this generation because he gets mixed reactions and lot of hate, he is nowhere close to the popularity of those two. Both Austin/Rock were loved and never got mixed reactions (unless they were heels). I think WWE really missed a huge opportunity with Cena. The guy had a unique gimmick (the 2003 thug), great mic work and even his move set was pretty good in 2002-2003. He would make his entrance rapping and destroying his opponent before they even fought, the fans loved it, it was kinda like attitude era Y2J/Rock. The thug gimmick really worked, he should have kept it and would have gotten over huge, it would have made WWE more money and fans wouldn't have hated him.
When WWE took the rapper gimmick away from Cena, they stripped him off his personality and character. If you watch any of his older videos you can clearly see how comfortable he was with the word life gimmick and how much fun he was having. With his marine gimmick you can easily tell that he isn't comfortable, he stutters a lot and gets lost for words and is very boring, his promos and pretty much the same and no longer unique like they used to be, each rap and each promo was different - kinda like Rock, each promo was different and entertaining which is why he became so successful and great on mic. Taking away the rapper gimmick from Cena is like Stone Cold Steve Austin turing into The Ring Master after his huge SOB character push and completely ditching his unique character and charm.
Another thing was that Cena's thug gimmick felt so real. In 2002-2003 in the real world, it was happening everywhere, you saw white guys trying to act black and trying to rap. It was everywhere, in your streets, college and high school. Cena represented that overgrown white kid at your school who was a big bully and a black guy wannabe, trying to rap and talking in ebonics - that guy you always hated and wanted to kick his ass. When people saw Cena on tv get his ass kicked it felt good cause you saw that bully in cena, it felt as if the bully was getting a lesson. Also back then eminem was very popular in the mainstream culture and so was rap, it helped alot to make his character feel real. Once in a lifetime do you get such a great character.
Fans started hating him either because he became the marine or because of his messy fucked up push.
To sum things up, a few points on what killed Cena
- messy mid card push
- losing to all big names in 2003
- the marine gimmick
- watering down the rap in 2004-2005
- face run that became boring real fast
- watering down his move set
- squashing the roster from 04-07
Just for old time sake, THIS IS THE REAL JOHN CENA: