Will,
My take is that amps are much easier to design that 6.1 pre/pro's. So each company can put its engineers to work to design something that looks and sounds like a homegrown design, thus offering some distinction from its competitors. Offering a pre/pro and amp combo that looks and specs just like 2 or 3 other companies would give you little to compete with, unless you were the cheapest, which they can't be due to Outlaw's business model.