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.