Jesus... Where do I start?
Honestly, nothing, but it's a very unimaginative and derivative style, post-50's that is. You have to color within the lines, and there's no innovation beyond trying to sound Chuck Berry-esque.
It worked for Morrissey for a minute. He's dabbled in various styles, so no biggie there.
Had he stuck with the sound as some kind of rockabilly niche act though, I think his career would have ended in 1990 something.
In my personal life though, the rockabillies I've known personify a dumbed down lifestyle of cars, alcohol, and a profound lack of self-knowledge or intellectual thought. At least the punks have a sense of humor.