Because to most people appearances matter and that website (or a beat up old car) doesn't speak to them having their proverbial shit together. Maybe that's not your case, but I wager that's true for the average person and therefore to the average consumer.

The HN audience is probably strongly correlated with the minority of people who think appearances doesn't matter as long as it gets the job done.

Please note that I'm not saying one of these outlooks is better than the other. I'm just saying most people care about appearance for better or worse.