#3 He wants to try something different
There is also a possibility of Randy Orton getting bored of doing the same thing of fighting for so many years. It could be a case where Orton is trying to create a different legacy of his own by doing something out of the norm.
It's pretty evident that Randy has changed his persona in a very subtle way and uses the term "R.K.O" as the three most dangerous letters in WWE. He's also showing a very vicious side of him where he's seen attacking the other wrestlers in a way he's actually never done before in his career.
He's inserted a screwdriver through Jeff Hardy's earlobe again and again. He's ripped off Rey Mysterio's in their match on Smackdown. Maybe this switch from Randy Orton is his way of making a change in his character which is portrayed to have a very vicious side to him.