I don't mind Orton, I'm not his biggest fan ever but I think he's sufficiently skilled to be in his position. Sure, he's not the most mind-blowing technician ever, but we as a group can be really negative sometimes, especially with regard to ourselves as a group. The IWC bashes no one as hard as it bashes itself, just look at what others have said in this thread.
Knowing how negative I can be, I do at least try to look for positives in everything, in every guy. Here are some key things that I think Orton does well that are integral to his success (by the way, these are all obvious things):
1) Sells his opponent's offence well
If you look at all the big faces ... they have to be good at this, it's instrumental during a match. If you look at how the crowd responds when Orton or Cena are getting beat up, or are locked in a chinlock, they begin to power out, audience builds up hope ... the claps start to build. It's not an easy thing to master, because you have to guide the emotions of several thousand people.
2)Characterisation/being a different face to Cena
I say 'being a different face to Cena', because the two are often compared, and as I see it, Cena was hated more than Orton until Orton was pushed to Cena's level. Now this point is another really obvious thing but that doesn't make it any less important. If Orton was just the SD version of Cena, it'd be boring. But he's anti-hero against Cena's happy-go-lucky boy scout character.
So we should be happy that the two top faces are entirely different in terms of character, right?
3) Orton is cool, or at least marketable that way
This is actually a major, major positive, I'm dead serious, and probably the prime reason you can push him as such a big face. He's got the almost robotic voice, that look in his eyes, and his hair and tats just add to this. It sounds corny but it's the main reason he's popular with the kids and the girls. His demographic is the slightly older ones than the Cena fans, but kids always want to like what's edgier, and Orton is definitely that compared to Cena. Does "RKO my own grandmother" clarify it clearly enough?
So those are the top three good traits of Orton in my view. Simple, obvious, but effective and certainly necessary.