I can see why people like cena an I can see why people hate him. To me he is a guy who got pushed to where he is rather than should've been there anyway. He can promo well to a degree and has charisma but his ability to come off as a 14 year old is unnerving. Oh and If you think he's brilliantly charismatic then I have some advice.
Go to
www.youtube.com type in "great one's greatest moments" and watch numbers 1 - 14 then come back wishing cena was that good. End of.