The thing I think people forget about Orton is that a third generation wrestler, he grew up watching Cowboy Bob live the life of a 1980's pro wrestler, which basically consisted of getting fucked up, nailing broads and breaking shit just for the pure joy of it. You look at other second generation wrestlers (Brian Christopher, Dustin Rhodes, Erik Watts, The Gilberts, Eddie Guerrero, The Von Erichs, Tully Blanchard etc) and they're all fucked up too.
I think Orton grew up with a certain understanding of a how a professional wrestler acts, and that is how he is behaving now.
Not making excuses for him, but I think it makes sense.