I beleive that there are two reasons people write sloppy code and get away with it: 1) They are lazy, 2) They don't want someone else to decipher what there writing, making it plainly (and painfully) theirs.

While I'm as lazy and the next person (read: male), I hate trying to decipher code that looks like something from the obfuscation page. This would be code that I have inherited for what ever reason. Let's face it, we are all expendible in the job market, so it is just as likely that you will move on to your next job and leave the poor slob who inherits your job a pile of muck, only to find out that the job you are going to has a bigger pile of muck to sift through. Not a good thing.
The other thing about writing usable but ugly code is that you will probably have to go back to it at some time. Then you realize that you don't have any idea what you have written. This is an even larger headache.

One other thing that I should mention about myself, I am a reformed anal-retentive. I'm just in the anal realm now. This probably explains a lot.