I think the biggest issue here is that it doesn't follow the formula:
"First note of recognition for audience's attention and huge pop, few seconds of build, wrestler enters, theme picks up pace and continues at the same level".
A majority of the themes that don't just sound like boring generic rock or hip hop music follow this pattern. Orton's new theme starts off in the same basic (if not faster) tempo, which doesn't allow for any psyching up or build. Essentially, his theme is as emotionally stirring as "Awaiting the Cage" is...you know, the repetitive humming beat that they play when they're lowering a cage around the ring.
Orton's theme isn't a bad song...its something to tap your foot to...but that's the problem. If you're just tapping you're foot slowly, your rhythm is the same as a lullaby: repetitive, lacking energy, and droning so that its tiresome. Its completely devoid of that jolt that gets you excited.
To those that say it fits Orton's character, it seems there's 2 arguments being presented. One is lyrics. While lyrics are, obviously, an important aspect of any song, the WWE's lyrics aren't as much of a necessity, since who is really paying attention to the music's lyrics while they're trying to take in the action itself? This is within reason, naturally. If you're trying to go with a masculine song, you don't want lyrics talking about strawberry scented muffins, unicorns, and fairies. But more importantly, you don't want Undertaker to be changed to a theme song where the lyrics talk about death and such, but the only instruments are a triangle, a flute, harp, and the highest pitch on a piano. Ambiance over lyrics. The other argument seems to be that Orton is slow, methodical, and this fits him much in the same realm as how Taker has slow music. Even though Orton isn't running around the ring like Kendrick, he doesn't have an imposing gimmick of intimidation like Taker does, so having a slow theme doesn't build up suspense, it kills it.
They could do worse...but they could do much, much better. In my opinion, the Mercy Drive song had all the essential elements to a good entrance theme, so why bother changing it?