why would any developer who didnt want to lose their job use this? There are lots of things you can do that you shouldn't. So what I can do with one background image and 2-3 divs and look good, you can do with a series of bold tags to look bad. Sorry to be critical, but this is not the quality of content I have come to expect from HN. Digg maybe.
because hackers like to do things with less work. creating images means work. the code does look long though. it should probably be abstracted into a server-side view helper function.
Less work in this case = horrible results. You're ruining the semantics of the DOM to use a crappy method for creating rounded corners. Want to create a fluid box with rounded corners and even less work? Use Javascript. You're not writing crappy HTML and it's even less work; just tag the <div /> with a class.
If the quality of the implementation weren't bad enough, this method isn't even new.