Actually, Jim Bede did the initial layout long before Rutan jointed the company
Jim Bede's first design concept was around 1970. Rutan didn't join him until a couple years later. While at Bede, Rutan saw the potential of the homebuilt movement and started working on his own designs, beginning with the VariViggen. The rest is history. I don't think Rutan couldn't design a "normal" looking plane if he tried, but then, who would want him to? He's the man.