Yea, I think this is part of the attitude problem actually.
Many sites are heralded as an example of 'no design necessary' because they lack the eye candy. However, the minimalism of these sites, the layout of results by date (as opposed to alphabetically or something else) the categories they are arranged by, all are part of the design of these sites. Was a designer involved in this? Hard to say, probably not, but were these decisions made intentionally by someone considering alternative choices? absolutely.
I'm not saying designers are the only people who can design. Just that designers are trained and have experience making decisions like the ones I mentioned above. We can - and do - provide value to software.
All three are very deliberately designed the way they are, and function well thanks to those designs. Good design is often "as little design as possible", as Dieter Rams' final principle for good design goes; avoiding overdesign is a merit, not a deficiency.
I disagree - those sites have great designs, they're just not pretty. There are a million different ways people use Craigslist so they put a million different links on the homepage to get as many areas as possible within one click of the mouse. HN and Reddit support thriving communities of non-assholes - look at how many sites with "better designs" have tards for community members. HN in particular may purposely be designed to keep away people who are attracted to a flowery design.
I can vouch for Reddit's community being a result of it's "poor design". Most people are turned off by giant walls of text. Reddit is actively trying to build a community out of people who are going to take the time out of their day to sort through a wall of text.
In this way, Reddit's 'poor design' serves a function of repelling undesirable people. If you want to repel people then go for a non-design. If you want to attract as many people as possible, or attract people who are turned on by something other than a wall of text, then hire a designer.
If the design is optional, why does Reddit have an 80k CSS file and Craigslist have a 14k one? (Admittedly, HN has a very tiny amount of design).
Design isn't necessarily about embellishment, but aesthetic choices. Good typography and color scheme choices don't have to be paired with elaborate graphics for a design to be good.
But more to the point of what you're saying, design is NOT optional. It is the essence of how people interact with your website/product. There are certainly some exceptions to the rule, but generally people flock to a more attractive product because it is attractive. Look at any Apple product for a perfect example of this. iOS is far less usable and powerful than Android, but people like it more because it's visually pleasing. OSS is never going to win unless it has that similar level of sex appeal in its products.
Other people have have said as much as I'm going to say but I just couldn't help but add my two cents.
The problem here is your very definition of design. If you were a designer, you'd be the bad kind that equates good design with over the top graphics. The best design is subtle. It doesn't call attention to itself or say "look at me." It just is. To paraphrase from the movie Helvetica, good design shouldn't make you say oh look how nice this design is—it should make you say well of course it's this way, why would it be any other way?
Take this very comment page, it's not flashy but I wouldn't say it's bad design at all. It knows it's audience isn't looking for bells and whistles. Everything lines up in a pleasing—and more importantly, logical—way. The typography is decent and there's enough differentiation between the comment and it's meta data. I could go on.
Basically, just open your mind. Bashing someone's profession without hearing their side is never smart.
The way there are upvotes and downvotes on reddit is an important part of the design. It has deep repercussions on the user's dynamics, the way posts get popular or are ignored, etc.
Now, purely font-choosing 'design' is not that important, but if you think that's design, you are misguided.
And this comes from a guy who just codes and does SQL queries all day.
