Why does an aircraft the size of the A380 have those stupid looking winglets from the A310/320 family? why didnt airbus give it the A330/340 style winglets? or why couldnt it have wing design that would not require winglets at all, like on the 777
I don't think those winglets on A320 family a/cs are stupid. They are actually quite special and unique. I think those A320 winglets is a sign/symbol of Airbus.
There is some goning concerns whether winglets can actually improve airplane's performance. Some studies found that winglets only do little help in reducing drags and fuel consumption. This is esp. true for short and medium haul flights, such as 777. (not ER ver.)
The A380 could do without them, I prefer the A330/340 and 744 style winglets as for the winglet study you mentioned above, yes its true, United Airlines carried it out on a 744 and were surprised by what they discovered