The benevolent dictator model works
A benevolent dictatorship has always been the most efficient form of government and of project management for that matter. As long as the bloke at the top stays sane and knows what he's doing 
For those of us who want a widely collaborative development effort, I don't think Arduino is gonna be it.
This is one reason I like the DuinoMite project. I think the hardware was a done deal by the designer but the software is certainly collaborative.
Maybe people aren't that interested in collaborating on hardware, I only got one response to my call to collaborate on a Due-like board and that was from a member that is mostly a software type (actually that was good because I'm mostly hardware). While it's easier in many ways to just do your own thing, however you usually get a better product if there are a few minds on the job.
Rob