Yes, audi had very good reasons to do it. First, it wouldn't be possible to fit these on 8v engines without crossflow heads. Second, they don't have proper air filter and, I presume, it costs more than standart filter. Third - there is no choke, so in winter there would be no idle when cold. Forth - such a short intake tract is for high rev power and not for low rev torque
Fifth - engine equipped with such carbs use a lot of fuel. Take a look on that video again, what's happening when that "someone" applies throttle for first time - I presume if that someone would apply full throttle at idle speed, that engine would stall
P.S. I personally think "carb fans" are just old minded people. Modern aftermarket programmable ECUs can provide compromise between power and daily usage[fuel economy and costs], carbs cannot provide both.