Do we need design specs anyway?

In a recent post , we saw two very different opinions on the need for functional specs.
 
The Fishbowl: Finding Discord in Harmony gives an unexpected reason NOT to want design specs, when you are starting up an open source project:
 
Most importantly, though: working code attracts people who want to code. Design documents attract people who want to talk about coding. I’ve seen what happens on projects that start with no code and a commitment to produce a design. Some of the procession of UML diagrams were really well put together, but that’s about the extent of it…