He's a great heel and a terrible face.
Unfortunately, he's SO good at being a heel, that every time he does it, people start cheering for him. And then WWE turns him into a bland face, cause they can't do a Stone Cold style face anymore in the PG era. So they he's boring, people stop caring.... and then the cycle repeats.
In a better era, with better writers, he could be one of the GOATs.
My favorite Randy Orton is probably the 2009, slow-walking, head-punting, psychotic, violent Randy Orton, who would react to hurting people with spasms like a heroin addict getting a heavy hit. Borderline orgasmic. In a darker, less-PG era, they would have run further with that, instead of doubling down on the 'snakey' pre-RKO mannerisms.
That said, IDGAF Randy who is happy to get into it with fans ringside and on twitter is pretty good too:
Also, for all the talk of how he's undeservedly pushed, he's been a victim of truly horrid booking every time he's gotten over organically.
In 2004, as the Legend Killer, he gets over, gets the title put on him, then gets turned face in a horrible angle with Evolution, only to lose every match against HHH exact a Survivor Series match.
In 2009, as the psychotic Orton, he gets over huge and picks off Evolution and the Mcmahon family one by one on the way to Wrestlemania. Then not only is he booked to lose a match he should have won, but a match that should have been a no-holds-barred war is booked as a 'if the champ gets DQed he loses' timid wrestling affair.
There are more examples. The truth is, yes, Orton got a lot of opportunities it wouldn't have otherwise if not for name, look, natural talent, etc. But there are a lot of cases where he used all those things to great effect and was rewarded with idiocy.