That I agree 100% with. I too believe that. Hell, I find myself liking simple layouts more than what's the usual startup trend for pretty backgrounds (and background videos; whoever does that deserves to have their Internet access limited to crappy 3G modem with fixed rate of $0.1/MB) and fluff.
Personally, I think HN is actually too simple. Reddit seems uglier, but they have lots of very small features that greatly support discussion on the site. I actually think that the interface for general discussion on-line lies somewhere between HN and Reddit - simple but useful tree-like forum.
Also, the orange bar is basically the single visual element that makes HN HN, so I don't know why people would even like to customize it...
There's some mystery here.
EDIT: I found one quote:
"So the most important thing a community site can do is attract the kind of people it wants. A site trying to be as big as possible wants to attract everyone. But a site aiming at a particular subset of users has to attract just those—and just as importantly, repel everyone else. I've made a conscious effort to do this on HN. The graphic design is as plain as possible, and the site rules discourage dramatic link titles. The goal is that the only thing to interest someone arriving at HN for the first time should be the ideas expressed there."
http://www.paulgraham.com/hackernews.html