Here is why design-by-committee doesn’t work based on my experience:
Everyone has a visual
Each person comes in with a mental picture of what it should look like. Very rarely does that mental image look the same as someone else’s. So each person tries to tweak the design more and more towards their mental image. That means each team member (even if they are dedicated to the team) is essentially working against the others.
Web designers (should) know best
The site doesn’t always look like the comp. Once a developer puts it on the web, there are media queries and different font renderings and screen sizes and accessibility concerns. The web designer is paid to think about all of these issues and should have a good idea of what his design will look like on the web.
Content is hard enough
Getting the content assembled correctly is a hard enough job for the rest of the people. Although they should have already had most of the content ready before the designer comes in, they should be finalizing and organizing that content to keep them busy.
Consistency is easier
One person can keep a design consistent. When all parties weigh in, then that consistency starts to fade away, often along with your user’s experience.
Assigning blame
Why give yourself multiple fail points? If your sites design goes live and the feedback is terrible, then at least you can eliminate pointing fingers at each other’s design input. Put that burden on one person and the team can avoid pointing fingers at each other.
Groups aren’t creative
Big corporations fail to innovate. There are exceptions but a readily observable fact is that big groups of people compromise or maintain the status quo almost every time. Individuals can be creative.
